UDP stands for "User Datagram Protocol." It is another fundamental protocol of the Internet Protocol suite (TCP/IP) that, unlike TCP, offers connectionless communication. UDP allows for the exchange of data between applications without requiring a prior connection. Compared to TCP, UDP provides fewer features for reliability and error handling, making it faster but less reliable.

Some key features of UDP include:

1. Connectionlessness: UDP does not require a prior connection between sender and receiver. Datagram packets are simply sent without requiring acknowledgment or monitoring of reception.

2. Low overhead: Compared to TCP, UDP has lower overhead because it provides fewer complex mechanisms for reliability and error handling.

3. Faster transmission: Because UDP offers fewer features for data transmission, it can be faster than TCP in certain applications.

4. Multicast and broadcast support: UDP supports multicast and broadcast communication, making it suitable for applications like audio and video streaming or online gaming.

UDP is commonly used in applications where fast data transmission is more important than reliability, such as real-time communication, streaming media, and online gaming.

TCP stands for "Transmission Control Protocol." It is a fundamental protocol of the Internet Protocol suite (TCP/IP), responsible for the reliable transmission of data across networks. TCP provides connection-oriented communication, ensuring reliable and sequential transmission of data between a sender and receiver.

Some of the key features of TCP include:

1. Reliability: TCP ensures that data packets arrive in the correct order and that no packets are lost. If a packet is not received properly, TCP requests a retransmission.

2. Flow control: TCP regulates the flow of data between sender and receiver to prevent receiver overload and avoid data loss.

3. Error detection and correction: TCP employs various mechanisms to detect and correct errors during data transmission.

4. Full-duplex communication: TCP enables bidirectional communication, allowing both sender and receiver to send and receive data simultaneously.

TCP is used by a wide range of applications on the internet, including web browsers, email clients, file transfer protocols, and many others. It is one of the foundational protocols that enable the internet, essential for transmitting data across the internet.