What is a protocol?

A protocol is a set of rules and agreements that define the format, timing, and sequence of data exchange between two or more entities (such as devices or programs) in a computer network.

Main functions of protocols:

• Data formatting: Defining the structure of messages.
• Addressing: Identifying the sender and receiver of data.
• Routing: Determining the path for data delivery.
• Error control: Detecting and correcting errors during transmission.
• Flow control: Regulating the data transfer rate to prevent overload.

Examples of network protocols:

• HTTP (Hypertext Transfer Protocol) – for transferring web pages.
• TCP (Transmission Control Protocol) – reliable data transfer with error control and flow management.
• IP (Internet Protocol) – for routing packets in a network.
• FTP (File Transfer Protocol) – for file transfer.
• SMTP (Simple Mail Transfer Protocol) – for sending emails.

Protocols play a key role in ensuring interaction and communication in distributed systems and networks.