Adefined set of standards that computers must follow in order to communicate properly is known as a

Protocol  is a defined set of standards that computers must follow

Explanation:

Simply protocol are rules which much must be followed in each and every place. In the same way, protocol are set of standards for communication between system. If systems needs to be connected for communication, then a protocol needs to be defined for effective communication. There are different types of protocol for each and every purpose. For eg.

TCP / IP – Mostly used protocol for communication

HTTP – Used to communicate between systems online

HTTPS – Similar to HTTP but to establish a secured connection