protocol

Definition

Generic term to describe a code of correct conduct. Also called "etiquette": a code of personal behavior.

We can distinguish three relevant elaborations on the term 'protocol' to make the concept more specific:

Communication protocol, a defined set of rules and regulations that determine how data is transmitted in telecommunications and computer networking
Cryptographic protocol, a protocol for encrypting messages
Decentralized network protocol, a protocol for operation of an open source peer-to-peer network where no single entity nor colluding group controls a majority of the network nodes
Paraphrased by @henkvancann from source on Wikipedia (click on individual links).