Which protocol has less overhead compared to TCP?

UDP, or User Datagram Protocol, is a connectionless protocol that is part of the Internet Protocol suite. Unlike TCP (Transmission Control Protocol), which establishes a connection before data transmission and includes mechanisms for ensuring reliable delivery and ordering of packets, UDP does not require such extensive overhead.

UDP simply encapsulates data into packets called datagrams and sends them to the destination without establishing a connection or ensuring that the packets arrive in order. This lack of session management and acknowledgments means that UDP introduces significantly less overhead than TCP. As a result, UDP is often used in applications where speed is critical and where occasional data loss is acceptable, such as video streaming, online gaming, or voice over IP (VoIP).

ICMP, while it also has lower overhead than TCP, primarily serves diagnostic and control purposes rather than general application data transport. FTP (File Transfer Protocol) and SFTP (SSH File Transfer Protocol) are both built on top of TCP and thus inherit its overhead characteristics, making them less suitable for scenarios prioritizing low-latency communication.