Handshake
A brief exchange in which two parts agree how they will communicate before getting to work.
Glossary
Protocol
An agreed set of rules for how messages are formed and exchanged.
In one line
An agreed set of rules for how messages are formed and exchanged.
Also calledcommunication rules
A protocol is the etiquette of communication. It defines the order of messages, their shape, and what each response means, so that both sides always know where they stand. With these rules in place, an exchange can proceed smoothly without confusion.
Drivers speak protocols fluently, following the agreed rules precisely so that every exchange with a component is understood exactly as intended. Precision matters here; a message that breaks the rules may be misread or ignored entirely.
A protocol works only when both sides follow it faithfully. The shared rules are what make cooperation possible, and they remain stable so that parts built separately can still understand one another perfectly when they meet.
Protocols also describe what should happen when something goes wrong. A well-designed one says how to recognise an error and how to recover, so that a single stumble does not bring the whole conversation to a halt.
In practice
In practice, a protocol is like the established way an air traffic controller and a pilot speak. Every message has a set form and a clear meaning, and both follow the same rules exactly, so nothing is misunderstood. Parts of a computer communicate with the same disciplined precision.
