User Datagram Protocol

The User Datagram Protocol, or UDP, is another widely used transport protocol. It's faster than TCP, but it is also less reliable. It speeds up communications by not requiring what’s known as a “handshake”, allowing data to be transferred before the receiving party agrees to the communication.

UDP/IP is usually utilized for streaming audio or video, as these are use cases where the risk of dropped packets (meaning, missing data) is outweighed by the need to keep the transmission real-time. For instance, when users are watching a video online, not every pixel has to be present for every frame of the video. Users would rather have the video play at normal speed than sit and wait for every bit of data to be delivered.

Source: Cloudflare