What is protocol in data communication? Explain with an example.

In data communication, protocol is a set of standard rules that the communicating parties — the sender, the receiver, and all other intermediate devices need to follow in order to have successful and reliable data communication.

For example, let's consider the Transmission Control Protocol/Internet Protocol (TCP/IP) suite, which is widely used for communication over the Internet. TCP/IP defines a set of protocols that govern how data is transmitted over networks. TCP (Transmission Control Protocol) ensures reliable, ordered, and error-checked delivery of data packets between devices. IP (Internet Protocol), on the other hand, handles the routing and addressing of data packets across networks.

When a user sends an email using a client like Outlook or Gmail, TCP/IP protocols come into play. TCP breaks the email message into packets, adds sequence numbers for reassembly, and ensures each packet arrives without errors. IP handles the routing of these packets over the Internet to reach the recipient's email server, where the packets are reassembled and the email is delivered to the recipient. This entire process relies on adherence to the TCP/IP protocol suite, demonstrating the role of protocols in data communication.