A protocol is a set of guidelines or rules to follow when communicating with others. Just as there are protocols for humans (etiquette, "diplomatic protocols", etc), computers also need protocols to be able to communicate and exchange information with each other.
In computing there are many different protocols, depending on the nature of the intended communication.
- Dynamic Host Configuration Protocol (DHCP) - see IP Address
- File Transfer Protocol (FTP, SFTP, FTPS)
- HyperText Transfer Protocol (HTTP)
- Internet Control Message Protocol (ICMP) is used by ping
- Internet Message Access Protocol (IMAP)
- Internet Protocol (IP)
- Network News Transfer Protocol (NNTP)
- Post Office Protocol (POP)
- Robots protocol - see Robots
- Simple Mail Transfer Protocol (SMTP)
- Transmission Control Protocol (TCP)
- User Datagram Protocol (UDP)
- Voice over IP protocols (VoIP)