What is the main characteristic of UDP compared to TCP?

The main characteristic of UDP (User Datagram Protocol) is that it operates in a connectionless manner. This means that UDP does not establish a connection before sending data, nor does it ensure that packets arrive at their destination. Each data packet, or datagram, is sent independently of others, which allows for faster transmission since there is no overhead associated with maintaining a connection or managing packet delivery.

In contrast to connection-oriented protocols like TCP (Transmission Control Protocol), where a connection must be established and maintained between the sender and receiver, UDP allows for sending messages without the need for prior setup. This characteristic makes UDP more suitable for applications where speed is more critical than reliability, such as live streaming or online gaming.

The other options highlight features that are characteristic of TCP rather than UDP. For example, connection-oriented communication and guaranteed delivery of packets are primary functions of TCP, which ensures data is transmitted in the correct order and delivers acknowledgments for received packets. Additionally, high congestion control mechanisms are a well-known part of TCP's capabilities to manage network traffic effectively.