What is generally considered a disadvantage of UDP compared to TCP?

The advantage of selecting that UDP does not guarantee message delivery is rooted in the fundamental design principles of both UDP and TCP.

UDP, or User Datagram Protocol, is a connectionless protocol that offers a simpler way to send messages without establishing a connection. This results in lower latency and less overhead, which is beneficial for time-sensitive applications like video streaming or gaming. However, this simplicity comes at the cost of reliability. UDP does not have built-in mechanisms for ensuring that packets are delivered to their intended destination, and therefore, it does not provide acknowledgments for received packets or retransmission of lost packets.

In contrast, TCP, or Transmission Control Protocol, is connection-oriented and provides reliable message delivery through features such as error checking, acknowledgment of receipt, and retransmission of lost packets. This makes TCP suitable for applications where data integrity and reliability are critical, such as web browsing or file transfers.

The statement about UDP lacking guarantees for message delivery highlights this key disadvantage, making it essential for users of UDP to implement their own mechanisms if they require delivery assurance. This can increase the complexity of application development, but fundamentally, the core disadvantage lies in the unreliability of data delivery when using UDP.