Definition

Communication protocol used across the Internet for especially time-sensitive transmissions such as video playback or DNS lookups, where dropping packets is preferable to waiting for delayed data.

Unlike TCP, UDP is connectionless, meaning it does not establish a connection before sending data, does not guarantee delivery and does not ensure that the order of packet delivery is consistent.

Despite its lack of reliability features, UDP is crucial for situations where the timely delivery of data is more important than the precise delivery of every single packet sent. It offers a trade-off between speed and reliability that is essential for real-time, multimedia, and other latency-sensitive applications.

Key Features

• Connectionless - There is no handshake process like in TCP, making UDP simpler and faster for scenarios where overhead of stablishing a connection is unncessary or detrimental.
• Speed - It is suitable for situations where speed is critical and occasional loss of packets is acceptable.
• No Guarantee of Delivery - Since there is no acknowledgement of receipt, the sender won't know if the packet has been lost or received.
• No Order Guarantee - Ordering of packets must be managed by the application layer if needed.
• Lightweight - UDP has a smaller packet header compared to TCP, which reduces amount of data beign transmitted over network, making it a lightweight option for certain applications.
• Broadcast and Multicast - Allows a single packet to be sent to multiple recipients efficiently.