What is electronic mail?


Electronic mail (email) is a way of sending and receiving messages and other electronic data via a computer network. One of the most common computer networks people use today is the Internet.

Other types of computer network are LAN (Local Area Network), WAN (Wide Area Network) and Intranet (a localised sort of internet). A computer network is a number of computers linked together which send and recieve electronic data between themselves using various 'languages' or protocols as a means of communication. Common protocols are IPX, used on Novell networks, and TCP/IP (Transmission Control Protocol/Internet Protocol) which is the protocol associated with the Internet.

In oder to send and receive electronic mail you need to have what is known as an email client. An email client is a program which acts as an iterface between yourself, the operating system, the hardware (e.g. serial port, modem) and the network. Common email clients include Pine (used on Unix systems), Microsoft Exchange, Netscape Communicator, Eudora and Pegasus Mail.

The process involved in sending an email is as follows:

Click on the blue, underlined, text here to send an email.

The transfer of electronic mail over a network involves a number of quite complicated procedures. For example, the text of an email is translated into digital data. The digital data is sent to a server on the network (NB: a server on a computer network is really just another computer, however, its job is to act as a go-between between yourself and other servers/routers on the network. It literally serves you, the client). As strange as it may sound, each piece (packet) of digital data is 'tagged' with a unigue digital code that distigushes it from all the other individual packets of digital data passing through the network. If you think, for example, of the billions of data packets being transmitted over the Internet every minute it becomes all the more amazing how anyone ever receives their own email and not somebody elses! Even more curious, TCP/IP allows for parts of your email to be re-directed via entirely different routes on the internet and still end up in your "In Box" as a coherent message. The process is quite complicated and can not be covered here.

On the internet POP (Point Of Presence) email services allow the user to send and receive electronic mail from different locations not confined to the particular ISP (Internet Service Provider) used to connect to the internet. Web mail - using a web browser to act as an interface for sending and receiving email - is also becomming common.

Most email clients are not confined to transmitting text messages. Files (picture files, sound files, etc) can be "attached" to an email for forwarding to anyone with a valid email address.

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