Refer to the following:
UDP is a connectionless protocol that transmits data without establishing a connection between the source and the endpoint before transmitting it, and when it wants to transmit it simply goes ahead and grabs the data coming from the application and throws it out onto the network as fast as it can. On the sending end, the speed at which UDP can transmit data is limited only by the speed at which the application can generate the data, the capabilities of the computer, and the bandwidth of the transmission; on the receiving end, UDP puts each message segment on a queue, and the application reads one message segment at a time from the queue.
Because no connection is established for transmitting data, there is no need to maintain connection status, including send/receive status, etc., so a single server can transmit the same message to multiple clients at the same time.