What is a Protocol?

Protocol is a standard set of regulations and requirements that allow two electronic items to connect to and exchange information with one another. They regulate data transmission among devices as well as within a network of linked devices through both error control and specifying which data compression method to use. In particular, they can decide (1) the method of error checking, (2) how to compact data (if required), (3) how the transmitting device signals that it has concluded sending data, and (4) how the receiving device signals that it has completed receiving data. 

Among the most common Internet protocols are FTP (File Transfer Protocol), HTTP (Hypertext Transfer Protocol), TCP/IP (Transfer Control Protocol/Internet Protocol), and SMTP (Simple Mail Transfer Protocol).