A network protocol is a set of established rules and conventions that determine how data is transmitted, received, and interpreted across computer networks. These protocols ensure reliable and secure communication between devices, regardless of their underlying hardware or software differences. Examples include TCP/IP, HTTP, and FTP. By following these protocols, devices can exchange information efficiently and accurately, preventing data loss or miscommunication. Network protocols also define error handling, data compression, and authentication methods, playing a crucial role in cybersecurity by safeguarding the integrity and confidentiality of transmitted data.