Answer:
The mechanism by which TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) communicate data differs in several ways.
TCP is a connection-oriented protocol, which means that before any data transmission occurs, a connection must be established between the sender and receiver. This connection is established through a three-way handshake, where the sender and receiver exchange SYN (synchronize) and ACK (acknowledge) packets. Once the connection is established, data can be sent in small packets from the sender to the receiver. Each packet contains a sequence number, which allows the receiver to reorder the packets if they arrive out of order. TCP also includes mechanisms for flow control and congestion control, which help ensure that data is transmitted efficiently and reliably. At the receiver's end, the packets are reassembled in the correct order, and an acknowledgment is sent back to the sender to confirm that the data was received successfully.
UDP, on the other hand, is a connectionless protocol. This means that no prior connection setup is required before data transmission. In UDP, the sender simply sends datagrams (packets) to the receiver without any acknowledgment or confirmation of receipt. UDP is often used in situations where real-time communication is crucial, such as video streaming or online gaming, as it offers lower latency compared to TCP. However, since there is no guarantee of delivery or order of packets, it is up to the application layer to handle any necessary error checking, retransmission, or reordering of packets if required.
In summary, TCP and UDP differ in terms of their connection-oriented/connectionless nature, reliability, and overhead. TCP provides reliable, ordered delivery of data with additional features such as flow control and congestion control, making it suitable for applications that require high reliability and accuracy. UDP, on the other hand, offers lower latency and is often used in scenarios where real-time communication is more important than reliability, such as video streaming or online gaming.