What is Network Protocol, how does it work?

A network protocol defines rules and conventions for communication between network devices. Protocols for computer networking all generally use packet switching techniques to send and receive messages in the form of packets.

Network protocols include mechanisms for devices to identify and make connections with each other, as well as formatting rules that specify how data is packaged into messages sent and received. Some protocols also support message acknowledgement and data compression designed for reliable and/or high-performance network communication. Hundreds of different computer network protocols have been developed each designed for specific purposes and environments.

A network protocol defines rules and conventions for communication between network devices. Protocols for computer networking all generally use packet switching techniques to send and receive messages in the form of packets.
Network protocols include mechanisms for devices to identify and make connections with each other, as well as formatting rules that specify how data is packaged into messages sent and received. Some protocols also support message acknowledgement and data compression designed for reliable and/or high-performance network communication. Hundreds of different computer network protocols have been developed each designed for specific purposes and environments

A "network protocol" (not capitalized) is a set of rules which define how one computer talks to another computer. So for example, a simplified version of a protocol might say "computer A will broadcast a message that indicates which computer it wishes to connect to, and computer B will respond. The computer A will send the first packet of data, and computer B will acknowledge it", etc.

Network protocols tend to be thick and highly detailed documents. Programmers use these documents to write the code that implements the protocol.

There is no protocol named "Network Protocol" (capitalized). The two protocols most famous in the world are IP (Internet Protocol) and TCP (Transmission Control Protocol). These protocols are essential elements of the Internet.