What is a protocol

 Rules for communication
 Description
 Format and method
 Understood by different types of computers

A protocol is a standard set of rules that determines how computers communicate with each other across networks.
A network is two or more computers that are physically connected to each other and able to share information.

When computers communicate with one another, they exchange a series of messages.
To understand and act on these messages, computers must agree on what a message means.
Examples of messages include establishing a connection to a remote machine; sending or receiving e-mail; and transferring files and data.


A protocol describes:
the format that a message must take, and
the way in which computers must exchange a message
within the context of a particular activity, such as sending messages across networks, exchanging e-mail, establishing remote connections, or transferring files.


Think of an electronic mail message. Both the format of the electronic mail message and the way that it is transmitted across the network are described and governed by a protocol.
Protocols ensure that electronic mail messages are correctly formatted and transmitted from the originating computer to the destination computer.
A comparison can be made to the rules that govern how letters are handled by the post office:




There are different protocols for different types of network services. For example, the Internet is based on the TCP/IP suite, or family, of protocols.
Some of the protocols used on the Internet are:
 Simple Mail Transfer Protocol (SMTP) - to send and receive electronic mail
 File Transfer Protocol (FTP) - to transfer files between computers
 Hypertext Transfer Protocol (HTTP) - to transmit information on the World Wide Web
 Network News Transfer Protocol (NNTP) - to transmit network news

Protocols enable different types of computers (Macintosh, PCs, UNIX, VMS, etc.) to communicate in spite of their differences. This is because they describe a standard format and method for communicating.
A very simple comparison can be made to Morse Code:
 People using Morse Code agree that a given combination of dots and dashes will always have the same meaning.
 Someone who speaks only Russian and someone who speaks only Greek can exchange messages using Morse Code because they agree on the format and method for exchanging messages.


Hope u take benifit of it
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Aras