Q.What is a protocol?

When two computers exchange data over a network, both ends must agree on exactly how the data is to be formatted, addressed, sent and acknowledged. A protocol is this agreed set of rules and procedures that a communication system follows so that devices can understand one another and exchange data in an orderly, reliable way. Without common protocols, computers built by different makers and running different software could not communicate at all.

The internet does not rely on a single protocol but on many, each handling a specific task, and they work together in layers. Four of the most important are:

• TCP (Transmission Control Protocol) — breaks data into packets and ensures they are delivered reliably and reassembled in the correct order;
• IP (Internet Protocol) — handles the addressing and routing of packets so they reach the right computer;
• FTP (File Transfer Protocol) — used to transfer files between computers; …