Explain the differences between TCP and UDP protocols and in which scenarios each is used.

TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are two main transport layer protocols in a network.

TCP is connection-oriented, provides reliable data delivery, order control, and integrity. It is used when reliability is important, for example:

• loading web pages (HTTP/HTTPS)
• file transfer
• email

UDP is connectionless, does not guarantee delivery or packet order, but is faster and has lower overhead. It is used in scenarios where speed is crucial and data loss is acceptable:

• streaming video and audio
• online gaming
• DNS queries

Thus, the choice between TCP and UDP depends on the requirements for reliability and data transfer speed.