What is Internet.

The Internet
DEFINITION (WHAT IT IS?)
The Internet Is a network of computers linking many different types of computers all over the network of networks sharing a common mechanism for addressing (identifying) computers, and a communication protocols for communications, between two computers on the network.

BRIEF HISTORY
The Internet has its root in the ARPANET system of the Advanced Research Project Agency Department of Defense. ARPANET was the first WAN and had 6nly four sites in 1969. The Internet < basic ideas of ARPANET for interconnecting computers, and was used by research organizations and initially to share and exchange information. In 1989, the U.S. Government lifted restrictions on use of the J and allowed it to be used for commercial purposes as well. Since then, the Internet has grown rapidly the worldjs largest network. It now interconnects more than 30,000 networks, allowing more than computers, and more than 50 million computer users in more than 150 countries around the world to witheachother. The Internet continues to grow at a rapid pace.

ITS BASIC SERVICES
There are four types of services provided by the Internet to its users. These are described below.
Electronic mail service (known as e-mail in short) enables an Internet user to send a mail {message) to another user in any part of the world in a near-real-time manner. An e-mail message takes a few seconds to / minutes to reach its destination, because it travels from one network to another, until it reaches its destination.
E-mail service has many similarities with postal mail service. AH Internet users have an e-mail address, just as all of  us have a postal address. Each Internet user has a logical mailbox, just as each one of us has a mailbox in our house. When sending a mail to another user, a sender specifies the e-mail address of the receiver, just as we write address of the receiver of a post in postal mail system. E-mail service delivers an already sent mail into its mailbox. The receiver extracts the mail from his/her mailbox and reads it at his/her own convenient
just as in a postal mail system. After reading the message, the receiver can save it, delete it, pass it to
else, of respond by sending another message back. .

Messages in e-mail -service can contain hot only text documents but also image, audio, and video data. Only fiction' is that the data must be digitized, that is, converted to a computer-readable format.
with e-mail service, the Internet has proved to be a’ rapid and  productive' communication  tool for millions of users, compared to paper mail, telephone, and fax many prefer e-mail because f its following advantages:

1.It is faster than paper mail.
2.Unlike telephone, the persons communicating need not be available at the same time.
3.Unlike fax documents, e-mail documents can be stored in a computer, "and cart be edited easily using editing programs.