Network protocols made the modernization of the Internet possible. Such protocols allow computers to communicate with other computers without users having to know what is happening in the background.
Network protocols are sets of rules for exchanging information. This exchange usually occurs much like a dialog between two computers. The exchange often begins with the client sending a signal to the server, providing key information about what kind of data is being requested.
Without a set of rules, computers would not have the capability of "talking" to each other across the Internet. Certain protocols help computers identify themselves on the Internet.
How Exchange Begins
The data exchange between computers on the Internet begins when the client introduces itself to the remote server it wants data from.
After the Handshake
Some exchanges between computers are in short bursts (such as HTTP) while others can stream for long periods of time (as in instant messaging). The server may send a bundle of data and then close the connection, or it may continue to interact with the client computer until the client decides to end the conversation.
When Rules Aren't Followed
Network protocols were created to allow computers to communicate in an organized manner without any room for misinterpretation. Clients that do not follow the rules oftentimes are disconnected by the server, or vice versa, depending on what the protocol specifications state.