Explain the essence of the UDP protocol and its main features.

UDP (User Datagram Protocol) is a transport protocol that provides data transfer without establishing a connection (connectionless). Key features of UDP:

• Connectionless: does not require a handshake, reducing delays.
• No delivery guarantee: packets may be lost, duplicated, or arrive out of order.
• Minimal overhead: UDP header is very simple, speeding up transmission.
• Suitable for applications where speed is more important than reliability: for example, streaming video, voice calls, games.

UDP does not provide error checking and delivery order, so the responsibility for this lies with the application.