Protocols used to govern and control data transmission

A protocol is a set of rules which must be adhered to; they ensure that all parties involved in the data exchange fully understand how to package and unpackage data, how to direct it etc.

Two of the most common transmission protocols are TCP or UDP.

The Internet relies on TCP/IP – that is, TCP is the primary network protocol, but it is sent via IP – which is Internet Protocol.

TCP is a ‘guaranteed’ delivery protocol; if data is sent, and no acknowledgement of receipt is made, then the data is re-sent. In a sense, TCP prioritises accuracy over speed – it doesn’t matter if re-sending data causes a delay, it is more important to ensure that the data arrives, and can be reconstructed.

UDP is, in contrast, a ‘best effort’ protocol which favours speed over reliability. Consider a live-stream of an event, or online gaming. It is far more important to have most of the data delivered as quickly as possible than it is to have all of the data. In a game, receiving data after it has been re-sent a third or fourth time would be pointless, as the situation it described (eg the position of enemies) would be out of date by the time it was finally received.