4. Protocol

A 'protocol' is an agreed way of doing something. In the case of ICT the most relevant protocols are to do with network and wireless communications. The image below shows a network socket on a laptop. The data flowing through this connection is following a certain protocol.

The entire World Wide Web is largely dependent on a communication protocol called TCP/IP short for Transmission Control Protocol and Internet Protocol. This protocol defines how data packets are to be handled by various equipment such as routers, network cards, hubs and so on.

There are other common protocols such as the RS232 protocol for serial communications. There is a protocol for file transfers over a network called FTP (File Transfer Protocol) which is the basis of uploading and downloading digital files such as MP3 tracks.

There are many other important protocols used for specialised purposes such as in-car networks and production machine communications in factories.

They all share the same advantage, namely that equipment made by different companies will operate with one another as long as they stick to the agreed protocol.