Communication protocol can be defined as sign, position, rule, minimum duration and color of each movement in semaphore flags.

In computing, a communication protocol refers to the set of rules that computers use to communicate with each other. The protocol defines the signals that the computers will give each other, and other details such as how communication begins and/or ends.

Types of Protocol

• Hypertext Transfer Protocol (HTTP), is used for accessing and receiving Hypertext Markup Language (HTML) files on the internet.
• Simple Mail Transfer Protocol (SMTP), is used for transferring e-mail between computers.
  • Post Office Protocol version 3 (PoP3) is the most common account type for personal e‑mail. Messages are typically deleted from the server when you check your e‑mail.
  • Internet Message Access Protocol (IMAP) is a protocol for e-mail retrieval and storage developed in 1986 at Stanford University as an alternative to POP.
• File Transfer Protocol (FTP), is used for showing files to be copied between devices.
• Transmission Control Protocol (TCP), ensures the delivery of information packets across networks.
• Internet Protocol (IP), is responsible for logical addressing called "IP address" to route information between networks.
• In computer networking, Point-to-Point Protocol (PPP) is a data link (layer 2) protocol used to establish a direct connection between two nodes.
• The packets and device protocol(TPADP) makes sure that the other protocols have a back up route.^[source?]