Internet is a cooperative interconnection of many single-entity networks such as Single Corporation, government agency, telecommunication networks. So Internet is called ‘Network of networks’. It overcomes the handicaps such as time differences, cultural variations.

 

E-mail

 

E-Mail(Electronic Mail)  is a very speed and inexpensive alternative to the conventional postal services. E-Mail is transfer from one computer to another along the network. Each computer reads the e-mail address and routes it to another computer until it eventually reaches it destination.

Every person has a unique e-mail address. E-Mail addresses are in the form of This email address is being protected from spambots. You need JavaScript enabled to view it.. For example This email address is being protected from spambots. You need JavaScript enabled to view it..

 

Protocols

 

Many protocols used in networking. Protocols defines the behavior of a hardware connection. A protocol is a convention or standard that controls or enables the connection, communication, and data transfer between computers. Some important protocols are HTTP, SMTP, POP3, TCP/IP.

 

HTTP: http gives a reliable transport. Resources used in http are identified by URI(Uniform Resource Identifiers) or URL (Uniform Resource Locators).

 

SMTP: It is the popular Internet protocol. It is used between the Internet hosts to transfer the e-mails from one computer to other. It’s destination for delivery is user’s e-mail box.

POP3: This protocol makes it possible for the TCP/IP dial-up account users to read, prepare and organize the emails in off-line.

 

TCP/IP:  There are two original components of the suite. One is TCP(Transmission Control Protocol) and the another one is IP(Internet Protocol). The entire suite is TCP/IP. IP handles lower level transmissions from computer to computer whereas TCP handles higher ends.

Computers are referred to in the press, on the radio and television. They now have invaded our govt. policies too.

If a developing nation has to invest in this technology, we must have a good set of reasons. Let us try to answer basic questions like

(1) What is computer?

(2) What can it do?

(3) How can one communicate with it?

(4) What are implications of computerization over a short as well as long period of time?

 

A computer was created for computing fast of purely mathematical function. Today they are used in all areas such as forecast the weather, to operate machines, to cut steel to size and even to guide a space craft to the moon. Computers help to trace criminals using Artificial Intelligence, today the whole world of airlines functions efficiently with the help of the computers. Hotels make use of them from managerial capacities to kitchen. Industries used for accounting, invoicing etc. India has excelled in this technology through the invention of the super computer par am -10000 which is supposed to be the second largest in the world

It is a electronic devices that replicate a cigar or other smoking pipes are called  "e-cigarettes"or "e-cigs". A public consultation on the discussion Anvisa (National Agency of Sanitary Surveillance) to prohibit the entry into the country of electronic cigarettes. These devices, usually made in China, are identical to a common cigarette in appearance and format, but contains no tobacco, but a refill for nicotine and flavorings. The idea of the inventors of e-cigarette was to create a device that does not release smoke pollution and help to contain the anxiety of smokers who can not let the smoke from the side. A study by the FDA, the U.S. agency equivalent to Anvisa, pointed out that these devices are just as carcinogenic as cigarette policy and recommended that its trading is suspended in the United States, where there is no rule prohibiting this. In Brazil, the legislation requires that any food, drug or product that affects human health to be recorded in Anvisa before being marketed. Nevertheless, electronic cigarettes can be found on newsstands, street trading or auction sites on the web. Sought by Plantao INFO, Anvisa said a public consultation in the final analysis is defining a standard that completely prohibit the entry of these devices in Brazil. Although their trade is not allowed, it is now possible to bring the e-cigarettes to the country on the grounds of their own use.   The electronic cigarette has a small nebulizer that generates steam every time the User aspires. The process removes nicotine and flavoring a refill inserted into the cigarette and generates a mist inhaled by the User. The idea is to simulate the effect of a common cigarette. Some models produce heat, and contains an orange lamp on the edge of the device in order to better simulate the burning of tobacco. The smoke exhaled by the consumers, producers say, would be composed only of water vapor and non-aggressive to the "passive smokers", people who are on the side of those who smoke. The whole process is fed by a lithium battery, which can be recharged. As the use of refill to quantitate the amount of nicotine consumed, in theory the electronic cigarette could help smokers to quit the addiction side, gradually diminishing the content of the substance in refills. On the Internet, these devices are found for between $ 150 and $ 300.

The internet is a vast network of computers, which links many different types of computers all over the world. It is a network of networks, which share a common instrument for identifying computers, and a common set of communication protocols for communication between two computers on the network. It has basically four types of services that are to be provided by the internet to its users which are:

1) Electronic mail - The electronic mail service, it is also known as e-mail allows user to send messages to another internet user in any part of the world in a very short time. The message takes anywhere in just a few seconds to arrive at its destination. It has many similarities with the postal mail services. It facilitates the user to use their email address and has own logical mailbox like each one of us has a mailbox in our house. It also has an alternative to the receivers, either it save or deletes.

Messages in email services can contain not only text documents, but also images, audio and video data. With email services, the Internet has proved to be quick and dynamic communication tool for its users. As compared to paper mail and telephone, email is preferred by many because of its advantages such as under follows:

1. It is more rapidly than paper mail.
2. Unlike telephone, the persons need not be available at the same time.
3. Unlike fax documents, email documents can be stored in a computer, and can be easily edited using editing programs.

2) File Transfer Protocol - The file protocol services, it is also known as FTP allows an internet user to move the file from one computer to another on the internet. A file may contain any type of digital information such as text document, images, artwork, movie, sound, software, etc. Hence, anything that can be stored on a computer can be moved with FTP service. Moving a file from a remote computer to one own computer is known as downloading the file, and moving a file from one’s own computer is known as uploading the file. Its takes place in the following method:

1. A user executes the ftp on his local computer, specifying the address of the remote computer as a parameter.
2. An FTP process running on the user’s computer establishes a link with an FTP process running on the remote computer.
3. The user is the prompted for login name and password to make sure that the user is allowed to access the remote computer.
4. After successful login, the preferred files are downloaded by using get (for downloading) a put (for uploading) commands.

But a user could transfer files from a remote computer, only if he has access rights for the remote computer. With this restriction, it is almost impossible to provide access rights to the vast number of the user of the internet to a computer that contain sharable information. The concept of anonymous FTP site is used to overcome this problem.

The anonymous FTP site is a computer, which allows the user to log in with the username of anonymous and a password that is the user’s email address. The user can than download files from the computers, which have been stored on it for sharing. Such are called publicly reachable sites because they can be accessed by any user on the internet. It is also used for more secure file transfer operations. In such cases, a user needs a valid username and password to access a particular computer.

3) Telnet - The telnet service allows an internet user to log in to another computer somewhere on the internet. That is, a user can execute the telnet command on his local computer to set up a login session on a remote computer. This act is also called “remote login”.

To start a remote login session, the user types the command telnet and the address of the remote computer of the terminal of his local computer. The user than receives the prompt asking to enter a login name i.e. user ID and a password to ensure that the user has the access right for accessing the remote computer. If the user specifies the accurate login name and password, he gets logged in to the remote computer. Once the login session is established with the remote computer, telnet enters the input mode, and anything typed on the terminal of the local computer by the user is sent to the remote computer for processing. It has some common uses such as:

1. Using the computing control of the remote computer. The local computer may be an ordinary personal computer and the remote computer may be powerful super computer.

2. Using software on the remote computer. The software that the user wants to use may not be accessible on the local computer.

3. Accessing remote computer’s database. The information records, such as the public database or library resources may be available on the remote computer.

4. For logging in to one’s own computer from another computer.

4) Usenet News - The Usenet services allow a group of internet users to exchange their views/ideas/information on some common subject, which is of interest to all the members belonging to the group. Several such groups exist on the internet and are called newsgroups.

It is like a notice board, which is accessible to all the members belonging to the group. A member, who wants to exchange his views with another member, sends a specially formatted message, which is processed and interpreted as a notice to be posted on the notice board by the member’s computer, which has an appropriate software running for this purpose. After the processing of the message is over, it can be read or seen from any member’s computer just like a notice posted to the notice board can be read by anyone having access to the notice board.

There are two types of newsgroup. First are moderated group and another one is non moderated group. In moderated newsgroup, only selected people have the right to directly post a message to the virtual notice board, whereas in a non moderated newsgroup, any member can directly post a message to the virtual notice board. In a moderated newsgroup, a message sent by any ordinary member first goes to the computer of one of the selected members having the right to directly post the message to the notice board.

The message is then checked by this member who decides whether the message is appropriate for being posted, and does any editing that might be required to improve the quality of the message. This member than posts the message on the notice board. After this only, the message becomes readable to (can be seen by) other members. The main idea of it is to ensure the quality of the newsgroup.

As no one moderates the quality of the message of a non moderated newsgroup, anyone can post anything. However the member of such newsgroup should be careful in posting a message, because other member may react angrily by sending a flaming message in response to an ill mannered message.