The Internet allows its users not only to send messages by e-mail, but also to communicate in real time, transmitting text entered from the keyboard literally in a matter of seconds to a common board. This service is called IRC (Internet Relay Chat) or Chat.
IRC (Internet Relay Chat, conversation over the Internet)- real-time conversation by typing text from the keyboard.
Unlike newsgroups, which support open discussion of a specific topic, in the IRC system, communication takes place within a single channel. Some channels operate permanently, while others are created temporarily. A user, having connected to the IRC system, usually selects a specific channel for himself, and then connects to it, choosing a nickname for himself. When you connect to a channel, you see on the screen messages sent to it by other participants. If you enter your message using the keyboard, it will almost immediately appear on the channel under your nickname.
Channel- organizing a discussion on a specific topic through the selected IRC system.
IRC server- a program that ensures the functionality of the IRC system and stores information about channels and connected users.
Several servers connected to each other form IRC system.
You can select channels within the same IRC system.
Special client programs have been developed to work with IRC servers. The most popular client is the mIRC program.
IRC client- a program for connecting to an IRC server and conducting a conversation (for example, a client: mIRC).
With development technical means computer networks the data transfer speed increases. This allows users connected to the network to not only exchange text messages, but also transmit sound and video over a considerable distance. One of the representatives of programs that implement communication via the network is the program NetMeeting , included in the kit Internet Explorer.
MS NetMeeting- a program that implements direct communication capabilities via the Internet.
It should be noted that to implement audio communication you need the appropriate technical equipment: sound card, microphone and Acustic systems. To transmit video images, you need a video card and a camera, or only a camera that supports the Video for Windows standard.
The main features of the MS NetMeeting program are:
- Connect to a directory server (ILS server), view the list of users registered on the server. When registering on any of the directory servers, you provide information about yourself, in particular, your country of residence and address Email. After connecting to the server, you can call any registered user and invite him to a conversation.
- Call a specific user through a directory server or local network by IP address or join an ongoing call. Call participants have equal rights. If you know your colleague's permanent IP address (which is extremely rare), you can call him directly, bypassing the server. If the person you're calling is already in the conversation, you can join. Equal rights of participants means that the conversation will automatically end if there is only one participant left.
- Organizing a meeting at the scheduled time (the meeting is controlled by a facilitator with special powers). The organizer of the meeting, as it were, retires to a separate room for a conversation and waits to join him. Special powers mean, firstly, the possibility of the sole presence of the presenter, and, secondly, the automatic completion of the meeting as soon as he leaves it.
After organizing a call or meeting, participants have access to various ways communication:
- Conversation (Chat) with meeting participants by entering text from the keyboard.
- Collaborate with graphics on a shared blackboard. Here the possibility of joint creativity is realized using the simplest graphic editor.
- Transfer any file to a meeting participant.
- Collaborate with a document (application) launched on the local computer by the meeting organizer. The host can choose to allow meeting participants to only view themselves while working with the running application, or grant any participant the right to work with the application.
- Voice and video communication during conversations. After setting up a call or meeting, you can have a phone-like conversation, send your video image, and see the image sent by the other party. If several people are participating in a meeting, audio and video communication can be carried out with only one participant. The quality of the picture and sound largely depends on the speed of your Internet connection.
The next type of service designed to provide communication and exchange of information between Internet users is paging services. The convenience and necessity of this service is due to the fact that, as a rule, most users do not have permanent IP address. Each time after connecting to the provider, the user is assigned a new address for the duration of the work session. By registering with a paging system and receiving your paging number, you can find the network IP address of the person connected to this moment to the Internet. The most popular Internet messenger is ICQ program. The title of the program uses a play on words; the expression I Seek You is read in a similar way.
ICQ- a system that implements paging-like communications via the Internet. Allows you to obtain a unique number called UIN (Universal Internet Number, universal Internet number), used for calling and direct communication. ICQ client can be downloaded for free from the servers www.icq.com or www.mirabilis.com.
After installing the program on your computer, you need to register in the server system ICQ and get UIN(Universal Internet Number, universal Internet number). This number (together with the password) identifies you as a registered user of the ICQ service. This number you can inform your colleagues, and then the system takes on the features of a pager. Every time you connect to the Internet, the ICQ program determines the current IP address of your computer and sends it to the central server. Knowing the UIN of the interlocutor, you can send him a message through the central server of the ICQ service inviting him to establish contact.
A remarkable feature of the system is to search for an ICQ network subscriber using indirect data, for example, by email address. After finding the desired subscriber, you can establish a direct connection with him. This way you can create your personal list of subscribers for communication.
After establishing a connection with subscribers, you can talk to them by sending text messages, similar to the IRC service. You can exchange files, send messages via regular email. The program has a very attractive interface, it can work in background, placing your icon in the form of a daisy on the taskbar, which takes on a different color depending on the connection. Icons on the taskbar flash when you receive various messages different shapes, attracting your attention.
IRC (Internet Relay Chat)- a service system with which you can communicate via the Internet with other people in real time. It was created in 1988 by Finnish student Jarko Oikarinen. In Russian computer slang, IRC is called “mirk” (tracing copy of the name of the most popular client - the program mIRC) .
IRC consists of servers. The server can be connected to other servers. A collection of servers connected to each other forms an IRC network. There are many networks in the world. The oldest and most famous are IRCNet and EfNet, formed from the split first IRC network.
To work with IRC you need special program- client. For Windows systems, the client is the program mIRC, which is easy to configure and install and therefore 90% of users use this program.
IRC provides the opportunity for both group and private communication. For group chat in IRC are intended channels, where users can gather and communicate. Communication is like communicating between people in a room - someone speaks and everyone hears him. Each channel has a name that reflects the general topic of the conversation. It can be either a topic that interests everyone, or just some name that unites everyone. If in the first case conversations are usually conducted around the specified topic, then in the second case conversations are conducted on completely different topics.
In addition to ordinary users of the IRC network, there are so-called channel operators and network operators. Channel operators are moderators, who keep order. They can block access to a channel without an invitation, exclude a user from the channel, give him ban(prohibition of entry to the channel) and much more. In the classic case, the channel operator is the one who first enters the channel and thereby creates it. Such channels have permanent operators. In order for them to receive operator status when entering the channel, those who are usually constantly sitting on the channel are used bots(robots), which have operator status and can distribute it to certain users.
IRC bots are programs that connect to an IRC server and can perform special operations. In addition to maintaining operator status, bots can perform the functions of a message board, display information about a user visiting a channel, etc.
IRC network operators- These are administrators who manage the operation of the network as a whole. They have the power to exclude a user from the server and prohibit him from logging into a particular server or even all servers on the network. However, as a rule, in IRC networks, restrictions are usually set for operators at the level of network rules, netiquette, or even at the level of IRC services ( IRC services).
IRC services are utility bots on IRC that typically include:
NickServ - service that manages users;
ChanServ - service that manages channels;
MemoServ - a service that allows you to send notes when the user is offline;
OperServ (RootServ) - a service that allows network operators to manage it;
Global - used to notify about server events;
HelpServ - Provides help for IRC services.
Also some versions of services contain:
BotServ - provides the opportunity for channel owners to invite bots to the channel;
HostServ (sometimes included in NickServ) - a service that allows you to change the user's real IP to a specific mask;
StatServ - statistics service;
DevNull - ignores all sent data;
SeenServ - displays data about the last time the user appeared on the server.
News organization
To make it easier to find the group of interest, all news is divided into topics and organized hierarchically, that is, similar issues are in lists next to each other. This structure resembles the directory structure of a hard drive. Programming in C, for example, is discussed in the news group comp.lang.c (here comp.lang is the hierarchy, and c is the name of the conference). Programming in Pascal is nearby, in the same hierarchy, but the group, as you might guess, is called pascal. Drawings are published in the alt.binaries.clip-art hierarchy (alt.binaries is the name of the hierarchy, clip-art is the name of the group). You can get acquainted with the work of poets and writers in Russian in the teleconference relcom.arts.qwerty, and with the dollar exchange rate in the conference with the characteristic name relcom.currency.
Teleconference subscription
The most pleasant feature of the subscription is its complete automation - a special program (newsserver) is engaged in servicing subscribers around the clock. At any time of the day you can subscribe to the topic you like or unsubscribe.
Since in many conferences (especially commercial ones) the volume of incoming materials is extremely large, you can subscribe only to the announcement titles (which is much cheaper), and then order articles of interest from them.
What is USENET
USENET is a community of people exchanging messages (or articles) within one or more newsgroups.
The structure of USENET is many news servers under various organizations, but USENET itself is not an organization or a network. This service is extremely widespread due to the fact that it is supported by a large number of networks and protocols other than the Internet.
How servers interact with each other, what protocols and procedures to use - all this is ultimately determined by the administrators (newsmaster) of neighboring servers. At the same time, USENET does not mean complete freedom. There are certain rules for creating new groups, distributing articles, materials, etc.
ProtocolNNTP
NNTP (Network News Transfer Protocol) is a network protocol used for exchanging messages in teleconferences. The structure of this protocol is in many ways similar to the SMTP email protocol.
There is a variation of the NNTP protocol called NNRP (Network News Readers Protocol). It is designed for reading conferences from a news server by client software online. Functionally, NNTP is focused on the fact that articles are sent to subscribers when they appear on the server, and NNRP is based on a client request. Accordingly, NNTP is used to exchange messages between news servers, and NNRP is used to read messages from the news server and create new messages.
The NNTP protocol, like SMTP, is text-based. An important feature of the NNTP protocol is its efficiency in the case of complex graphs of connections between news servers. To prevent the same message from being sent multiple times, usually the sending server first reports the identifier of the new message, and sends the message itself only after the receiving party confirms that this message is not there yet
Often news servers keep one or more NNTP sessions open at all times, so as not to open them every time they receive new messages.
Internet Relay Chat
IRC (English Internet Relay Chat - relayed Internet chat) is a service system with which you can communicate via the Internet with other people in real time. In Russian computer slang, IRC is called “irka”, “irets”, as well as “mirk”, “mirka”.
IRC is a program that allows you to have live conversations from your keyboard with people around the world. It is very similar to an international radiotelephone - and even uses “channels”. As soon as a user enters a message on their computer, it will immediately appear around the world to everyone who happens to be on the same channel with them. The user can join an existing conversation or start their own. It is even possible to create a private channel for a small number of people - at least one or two.
IRC currently integrates systems in 20 different countries, from Australia to Hong Kong to Israel. When connecting to an IRC server, the user sees a list of available channels, each of which (or several at once) he can “enter” (connect). A channel is a virtual “room” that can contain multiple users. All messages issued to a channel are visible to all users who are only on the same channel. Each channel has its own name and, as a rule, a specific topic for discussion. After “entering” the channel, the user can see what other channel members are writing, and can also write messages himself. The topic discussed on the channel usually follows from its name (for example, the Wikipedia.ru channel).
IRC clients are:
For Unix-like operating systems: XChat, Kopete, irssi, kvirc and ircII;
For Windows systems: mIRC, XChat, irssi, kvirc;
For mobile phones(MIDP): jmirc-m, snirc.
For OS/2: OpenChat
IRC provides the opportunity for both group and private communication. Group chat on IRC provides channels where users can gather and communicate.
Channels, like rooms, can be open to everyone, but there are also closed channels that can be accessed with a key or by special invitation. The channel can even be secret: in this case, it is not visible in the list of channels and, in addition, no one outside can see who is in it. This creates good opportunities for private conversations that no one can interfere with.
Each person communicating on IRC has a nickname (Nick), by which he is known on IRC. One of the great things about IRC is that it allows for parallel communication.
Despite the complexity of the technical structure of IRC, communication itself relieves us of some of the difficulties characteristic of traditional methods of communication.
4.1. History of origin
The abbreviation "IRC" stands for "Internet Relay Chat" and is a system that allows users to communicate with other Internet users. IRC was originally developed in 1988 by Jarkko Oikarinen and spread throughout the world over the following years. Although the system was initially conceived as an extension of the talk program, designed for communication between two users of UNIX systems, the results exceeded all expectations - a new communication system was born that changed the lives of many people.
IRC began to gain particular popularity after Operation Desert Storm (1991), when messages from all over the world were collected in one place and broadcast online on IRC. IRC was used in a similar way in 1993, during the coup in Russia, when users from Moscow reported to the world in real time what was happening on the streets. What can IRC do? Firstly, the joy of communication. People come to IRC to have a good time - for example, MTV or Zhurnal.ru periodically organize conferences on IRC, where famous musicians or writers are invited. On IRC you can find new friends; chat on professional topics, discuss the latest film and much more. There are real-time learning technologies that use IRC.
Advantages and disadvantagesIRC
The main advantages of IRC are:
IRC consumes a very small amount of traffic, which is especially important with a limited Internet tariff plan.
IRC allows the user to communicate with many people from other cities and countries.
IRC is an opportunity to make permanent online acquaintances and recognize them when they appear on IRC.
IRC is a flexible tool for people to appreciate your ingenuity, resourcefulness, and sophistication.
Delays when working with IRC do not exceed a few seconds. This happens due to the fact that the computer does not need to establish dozens of connections with other countries - it is enough to connect to the nearest IRC server.
Unfortunately, the IRC system is not without its drawbacks.
Sadly, it has become a kind of meeting place for the most unpleasant personalities, whose goal is not to communicate with other people, but to spoil their mood. They do this with the help of various kinds of dirty tricks, such as sending programs with “surprises” (malevolent bots), flooding (sending large amounts of data or repeating a certain sequence of actions that interfere with the conversation of other users), all kinds of pompous tirades, curses - in general, who knows what. There are many ways to protect yourself from such people, but getting rid of them completely is very difficult. Operators control order on the IRC network.
Why are operators needed?
Channel operators are the main ones on an IRC channel. They are distinguished by the "@" symbol before the alias. Typically, operator status can be freely transferred (or taken away) by other operators. An operator (or op for short) can kick (throw out) other users from a channel, block entry to a specific channel using some kind of mask, etc. Operator status is only valid within one channel.
IRC operators are the managers of IRC networks. As a rule, these are administrators of IRC servers; they do not interfere in internal conflicts and only remind of their presence when someone tries to interfere with the normal operation of the IRC network. The IRC operator can “kick” a user out of the network or even completely block access to the IRC network.
Connection toIRC
To work with IRC you need a special client program. For Unix systems, the most common client is XChat. For Windows this is the mIRC program. It is so easy to set up and install that 90% use it and often unknowing people call IRC a little world. Next you need to connect to the server. To do this, you need to type /server www.server.net address.
After connecting to the server, you can find the right person and communicate with him. You can also join a channel. Communication on the channel is similar to communication between people in a room. Someone speaks and everyone hears him. Each channel has a name that reflects the general topic of the conversation. It can be either a topic that interests everyone, or just some name that unites everyone. If in the first case conversations are usually conducted around the specified topic, then in the second case conversations are conducted on completely different topics.
Bots are programs that connect to an IRC server and can perform special operations. In addition to supporting operator status, bots can perform the functions of a message board, can display information about a user visiting a channel, and have many other useful functions.
If questions arise, but there is a specialized #help channel to answer questions, it exists on any self-respecting server or network. It is possible to create and moderate a channel on IRC yourself.
IRC-networks
The IRC client program establishes a connection to the nearest IRC server. IRC servers are interconnected. Thus, it turns out to be a kind of “network within a network” - you just need to connect to any of its servers to start communicating. Channel names begin with a hash ("#"), this is a common convention.
In order to select a channel, you can use the list offered by the client program. The IRC network consists of servers. The server can be connected to other servers. A collection of servers connected to each other forms a network. Initially, there was only one IRC network, but later it split into several parts (IRCnet, EFNet), new networks appeared (GalaxyNet, Undernet, others) and this process continues.
Teleconferences Usenet
Abstract >> Computer ScienceInteresting and educational. Global net Internet is... technology teleconferences. Teleconference well... Usenet is computer net with the help... in electronic mail, but unlike electronic mail this file... IRC Service Service IRC ( Internet Relay Chat- « ...
Computer technologies in merchandising and examination of goods
Abstract >> Culture and art... networks, which will be widely used global networks... level service. WITH... electronic publications and electronic directories, file sharing modes and electronic mail ... electronic document flow. Creation Tools electronic document flow. Computer ...
Electronic commerce legal regulation and taxation
Abstract >> State and lawRegulations electronic commerce - electronic economic activities carried out in the information environment global computer networks Internet using electronic funds...
ProtocolsIRCAbstract >> Communications and communications
Society is Global Information Infrastructure... (ATM, Frame Relay, X.25 and... access Internet, electronic mail, teleconferences(chat, forum... -directory) DNS service(maintaining primary/... is used in computer networks because it allows...
Email address can be obtained on the mail server e-mail mailing lists teleconferences ICQ service file archives search servers IRC service
An email address consists of two parts, where to whom email mailing lists teleconferences ICQ service file archives search servers IRC service
Advantages 1. high speed forwarding 2. forwards not only text, but also... 3. a letter can be sent to several recipients at once 4. you can turn on an answering machine 5. you can create rules for performing actions with similar messages (black list of advertising addresses) e-mail mailing lists teleconferences ICQ service file archives search servers IRC service
SMTP -Simple Mail Transfer Protocol Establishes two-way communication between sender and recipient mail message: The sender initiates the connection and sends service requests, and the receiver responds to these requests. e-mail mailing lists teleconferences ICQ service file archives search servers IRC service
POP3 -Post Office Protocol, version 3 Designed to forward mail from users' mailboxes on a mail server to their workplaces. Messages can be received, but cannot be sent. e-mail mailing lists teleconferences ICQ service file archives search servers IRC service
1. Create an email message on your local computer 2. Connect to the Internet, deliver the message to your Mailbox on a remote mail server 3. Delivery to the recipient's mail server 4. The recipient connects to the Internet and delivers mail from his mailbox to local computer e-mail mailing lists teleconferences ICQ service file archives search servers IRC service
Mailing lists - These are special topic servers that collect information on certain topics and forward it to subscribers in the form of email messages. e-mail mailing lists teleconferences IRC service ICQ service file archives search servers
Conference email address subscriber Each participant receives all materials to his email address Each subscriber email reaches all participants email mailing lists teleconferences ICQ service file archives search servers IRC service
The sheer volume of messages in newsgroups makes targeted monitoring difficult. Therefore, in some groups a preliminary “screening” of demons is carried out. useful information. Such conferences are called moderated. The moderator can be either a person or a special program that filters messages by keywords. e-mail mailing lists teleconferences ICQ service file archives search servers IRC service
IRC service Designed for direct communication between several people in real time. Communication takes place within one channel, in which only a few people take part. Each user can create their own channel and invite other participants to it. - Internet Relay Chat chat conference The most popular client program for working with the IRC service is mIRC.exe e-mail mailing lists teleconferences ICQ service file archives search servers IRC service
I seek you ICQ Service Designed for searching network IP address person currently connected to the Internet. The need for such a service is due to the fact that most Internet users have a dynamic IP address. - acronym for expression - I'm looking for you e-mail mailing lists teleconferences ICQ service file archives search servers IRC service
ICQ Service To use this service, you must register on its central server and receive a personal identification number UIN. This number is communicated to your contact partners, then the ICQ service takes on the character of an Internet pager. You can contact your partner by UIN number, the IP address will be determined by the central ICQ server. e-mail mailing lists teleconferences ICQ service file archives search servers IRC service
Software on FTP servers: Beta versions - unfinished programs for testing Patches - improvements to previously released programs Drivers, etc. With a limited validity period With limited capabilities 1. Protected information - with access under a special agreement 2. Information of limited use (shareware - shareware) 3. Information of free use (freeware - free) e-mail mailing lists teleconferences ICQ service file archives search servers IRC service
Thanks to the use of various network protocols The Internet can provide two main functions:
be a means of communication between remote users;
· be a means of access to common information resources posted on the Internet.
Obviously, each of these functions can be implemented through different means, resulting in a variety of services provided to Internet users. The means of providing certain services to users of the global network are usually called Internet services. At the same time, communication services provide communication between remote users, and information services enable users to access certain information resources stored on the Internet.
Communication Services
Obviously, there can be only two modes of communication on the network: the mode of direct communication in real time, when users are connected to each other during communication. An analogue of such communication is talking on the phone. Sometimes the term on-line is used to refer to this mode. Another mode is the delayed communication mode (off-line). An example of such communication in everyday life is sending a letter or telegram.
Direct communication on the Internet
Direct communication forums - IRC (Internet Relay Chat)
This system allows Internet and Intranet users to chat in real time. To receive this service, users must join channels that support different discussion topics. Any characters entered through the IRC program appear on the screens of all other participants in your channel. The technology for using IRC has much in common with working in Usenet conferences. But if communication there takes place in deferred mode, then a live conversation can take place here. The peculiarity of this communication is that the text of the message is entered using the keyboard and then appears on the general display. Thus, when using this service, communication between participants occurs on-line in written form. Similar to teleconferences, chat conference participants are divided into thematic groups.
Currently communication in " chat“is used as a kind of game in which each participant usually comes up with some kind of “image” for himself and plays it out. It is not customary for chat participants to communicate real communication. However, the chat service can also be used for serious communication - both collective and personal. One of the popular programs that provides work in this mode, is ICQ. In November 1996 the first ICQ version(I seek you, i.e. “I am looking for you”) was launched on the Internet and has since spread like an avalanche. It can be downloaded for free from the website: http://www.mirabilis.com. After installing the program, it will automatically download when you connect to the Internet.
Internet telephony
This service provides the opportunity for voice communication via the Internet in on-line mode. This is a new, developing service. Its main advantage over the telephone is its low price. The quality of Internet telephony is still inferior telephone communication(time delays, sound distortion), but over time these shortcomings are gradually overcome.
The general operating principle of IP telephony telephone servers is as follows: on the one hand, the server is connected to telephone lines and can connect to any telephone in the world. On the other hand, the server is connected to the Internet and can communicate with any computer in the world. The server receives a standard telephone signal, digitizes it (if it is not originally digital), compresses it, splits it into packets and sends it over the Internet to its destination using the Internet Protocol (TCP/IP). For packets coming from the Network to the telephone server and going into the telephone line, the operation occurs in the reverse order.
IP telephony technology combines circuit-switched networks (transmitting voice information) and packet-switched networks (transmitting data) into a single communication network. Seamless voice recognition and transmission from one network to another is solved using various gateways. As shown in Fig. 1, a gateway is a device that includes telephone lines on one side and an IP network on the other side.
Rice. 1. Scheme of operation of IP telephony
Voice, like analog vibrations in an IP telephony system, exists only in the handset. In the remaining sections of the transmission channel from subscriber to subscriber, speech is digitized and transmitted in the form of IP packets. Packets arriving at the gateway closest to the other subscriber are converted back into analog form (voice signal) and are sent to the telephone line. The most widely used in practice Skype program(pronounced "skype") - free program, providing encrypted voice communication via the Internet between computers (VoIP), as well as paid services for communication with regular subscribers telephone network. You can download the program from the website at http://www.skype.com/intl/ru/home.
Telnet service
This service provides interaction with remote computer. It allows you to turn the user's computer into a remote terminal of another computer. Therefore, this service is also called e remote terminal simulation. Terminal from regular computer differs in that it does not perform its own calculations. Everything that is entered on the workstation keyboard is transmitted to the remote computer, and the resulting results are transmitted back and displayed on the workstation monitor. The remote computers are mainly machines running under operating system UNIX [Unix]. Therefore, working in remote terminal mode requires knowledge of the basic commands of this operating system. With the development of graphical operating systems such as Windows, command mode work became less popular, and Telnet service V Lately most users don't use it. Many information systems previously available exclusively through Telnet, today are available from the World Wide Web, which will be discussed below.
Having established a connection using Telnet, the user gets the opportunity to work with the remote computer as if it were “his own”, i.e. theoretically have all resources at your disposal if access to them is allowed. Really Telnet provides open access, but the organization of interaction is completely determined by the remote computer. Two types of Internet services require connection to servers via Telnet: library catalogs and electronic bulletin boards (BBS).
Work with a remote system can be carried out in a “transparent” mode, when programs on the server and the client only provide the connection protocol, and in a command mode, when the client receives a set of server commands at its disposal. It should be noted that for security reasons there is a tendency to reduce the number of Internet nodes that allow the use of Telnet to connect to them.
Delayed communication on the Internet
Email - Email
This is the oldest and one of the most popular services on the Internet. Its purpose is to support the exchange of emails between users. At its essence, e-mail is a system for exchanging electronic messages in computer networks (in delayed communication mode - offline). The email operation diagram is shown in Fig. 2. A mail server is a kind of post office that receives incoming and outgoing correspondence from users registered on it. This correspondence is placed in users' "mailboxes" - specially designated sections on the hard drive. Each user receives a personal mailing address at which letters will be sent to him. It should be noted that email addresses are somewhat different from other Internet addresses, but very similar. They consist of two parts, separated by the @ symbol. To the right of the symbol is the Internet address of the computer on which the subscriber's post office is located. This address is formed in the same way as any other Domain name in the Internet. To the left of the @ symbol is the subscriber's name. An example of a postal address would be: [email protected].
Rice. 2. Email operation scheme
In order for this service to become accessible to the user, it is necessary to perform a number of procedures. First, the user must register on the mail server. This records the client's email address and password - a set of characters that allows the user to be identified. The presence of a password ensures the confidentiality of this service. A registered user has the opportunity to write the text of the letter, indicating the recipient's address. For this purpose, a letter preparation editor is included in the email client program. Prepared letters are placed in the Outbox folder. The server receives all letters from the Outbox folder and, in addition, transmits received letters, which are placed in the Inbox folder. The user's connection to the mail server is necessary only for sending letters and delivering letters from the inbox to the user's computer. The mail server is constantly running. It periodically looks through “mailboxes” and organizes the transmission of outgoing letters over the network. The mail server arranges incoming correspondence into “boxes”.
In addition to the function of receiving and transmitting letters during a communication session, the email client program can perform many more service functions:
· preparation and editing of letters,
· organization address book,
· viewing the mail archive,
· sorting and deleting letters from the mail archive, etc.
A popular E-mail client is Outlook Express, which comes standard with the MS Windows operating system.
The email server and client operate using different protocols. The POP3 (Post Office Protocol) server program, among other things, performs the function of protecting information. During a communication session, it establishes the user’s identity and provides communication with his personal mailbox. When operating the client program, no identification is required. Its task is to transmit outgoing letters to the server and receive incoming ones. It uses the simpler SMTP protocol (Simple Mail Transfer Protocol).
Teleconferencing service
A teleconference is a system for exchanging electronic messages on a specific topic between network subscribers (in delayed communication mode - offline). Each participant receives all materials to his or her email address (E:mail). Each subscriber's e-mail is published on the teleconference server and reaches all participants. (Fig.3).
Rice. 3. Teleconference operation scheme
Unlike e-mail, when a user sends his letter personally to a subscriber or group of subscribers, in teleconferences the letter is sent simultaneously to all its participants. In turn, all messages that arrive at the conference will be sent to the user's mailbox and downloaded to his computer during the communication session. To participate in the teleconference, you must subscribe to it. There are specific addresses for these purposes. Each conference is devoted to a specific topic, so correspondence in it occurs only within the framework of the topic. According to some estimates, the number of ongoing online conferences has exceeded 50,000.
The newsgroup service is called by many names: newsgroups, Usenet service. At Network nodes, news servers service teleconferences. A news client program must be installed on the user's PC. The above-mentioned MS Outlook Express program is at the same time mail client and news client.
Teleconferences combine both communication and information functions. On the one hand, personal communication takes place here, on the other hand, the conference materials contain a large amount of useful information, which certain time is stored on the server. This information can be considered as some kind of information resource (electronic newspaper). This is especially important for specialists participating in conferences on professional topics: science, production, business, trade, etc. In the conference materials you can find valuable advice and consultations that will help in making important decisions.
Information services
Information services provide users with the ability to access certain information resources stored on the Internet. Such resources are either files in one of the generally accepted formats or various documents. The use of these resources is provided through the corresponding services.
File Transfer Service
This service is often referred to by the name of the protocol it uses: FTP (File Transfer Protocol). On the Network side, the service is provided by so-called FTP servers, and on the user side by FTP clients. The purpose of an FTP server is to store a set of files for a wide variety of purposes (usually in archived form). Most often this program files: system and application software tools. But sets can store files of any other formats: graphic, audio, MS Word, MS Excel documents, etc. All this information forms a hierarchical structure of folders (directories and subdirectories).
After connecting the FTP client to the server, the user's screen opens file interface storage of folders and files on the server (like Windows Explorer). Further work proceeds in the same way as with file system on a PC: folders and files can be viewed, sorted, and copied to your disks. FTP client included in Internet programs Explorer and is therefore always available on a PC running MS Windows.
File sharing
A file hosting service is a service that provides the user with a place to store his files and 24/7 access to them via the web, usually via the http protocol (and possibly via FTP). This service allows you to conveniently “exchange” files.
On the central page of the file hosting service, the user uploads a file to the file hosting server, and the file hosting service gives the user a permanent link, which he can send by e-mail, publish on blogs, forums, or send via instant messaging systems (ICQ, MailAgent, IM, etc. .).
World Wide Web (WWW)
WWW- this is distributed Information system with hyperconnections, existing on the technical base of the worldwide computer network Internet. This information system is a network of documents interconnected by hyperlinks. Such documents are called hypertext. Since links can point to any document located on the Internet anywhere in the world, this system and is called the World Wide Web.
Smallest information unit WWW is Web- a page that is a collection of text, graphic and multimedia files linked by hyperlinks. Group Web pages belonging to the same owner and related to each other in content, constitute Web site. Host - a computer designed to store Web pages And Web- sites are called Web server. Client-program, intended for viewing Web sites, called a browser (from English browse - view, scroll through).
Browser(from the English Web browser; browser option - outdated form) - software for browsing websites, that is, for requesting web pages (mainly from the Internet), processing them, displaying them and moving from one page to another.
Most browsers can also display a table of contents for FTP servers.
Browsers have constantly evolved since the birth of the World Wide Web and, with its growth, have become increasingly popular programs. Nowadays, a browser is a complex application for processing and displaying various components of a web page and for providing an interface between a website and its visitor. Almost all popular browsers are distributed free of charge or “bundled” with other applications: Internet Explorer (together with Microsoft Windows), Mozilla Firefox (free, open source, compatible with some Linux distributions, such as Ubuntu), Safari (shared with Mac OS X and free for Microsoft Windows), Google Chrome(free), Opera (free since version 8.50).
Electronic media
Electronic media (media) are a convenient means of obtaining current information. Almost all modern newspapers, magazines, radio stations, television channels (Russian and foreign) have their own websites on the Internet where you can read the news, listen and watch information messages(including in real time). On the website www.karta-smi.ru you can find links to Russian electronic media.
The electronic version of the newspaper allows you not only to read the latest issue, write and send a review of what you read to the editor, but also to gain access to a file of old issues of the newspaper. On the websites of TV channels you can watch news programs and TV shows, participate in on-line conferences and forums, discuss what you see, and express your opinion. On the websites of radio stations you can listen to news programs and radio broadcasts on-line.
Comprehensive Internet Services
The introduction of the Internet into practical activities has led to the emergence of new services that combine both communication and information capabilities of the global network. These include:
On-line translators and dictionaries
Using on-line translators and dictionaries on the Internet, you can translate texts from Russian into English and vice versa.
This way you can translate texts emails, website content, etc.
Online stores
In online stores you can choose a wide variety of products, place an order, and the selected products will be delivered to your home. In this way you can purchase, for example, CDs, educational and fiction literature. As a rule, such purchases are cheaper than in regular stores.
Electronic payment systems
Systems electronic payments allow you to pay for a wide range of services, in particular, make utility payments. The scheme by which electronic payment systems work is extremely simple for the user. By registering in the system, you automatically open your account. Having credited the required amount of money to it in a way convenient for you, you can use it for settlements with partners of this system.
The most widespread payment systems in Russia are:
· Qiwi, currency - Russian rubles
· Yandex.Money, currency - Russian rubles
· WebMoney, currency - Russian rubles, euros, US dollars, hryvnias, etc.
These systems are easy to use. For example, to safely and quickly pay for goods and housing and communal services on the Internet, you can use the Yandex system. Money. To do this, you need to go to the Yandex.Money website or money.yandex.ru, register and create an electronic account.
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