What does multicast refer to in network communications?

Multicast refers to a method for transferring data to multiple users simultaneously in network communications. This technique allows a sender to send one stream of data to multiple recipients who have expressed interest in receiving that data, rather than needing to send individual copies to each user. This is particularly efficient in scenarios where the same data needs to be delivered to a large group of users, such as in live broadcasts or online streaming services.

The key aspect of multicast is that it uses networking protocols designed for efficient data distribution, reducing bandwidth usage compared to unicast (where data is sent to one recipient at a time) and broadcasting (where data is sent to all devices on a network). This is why multicast is often used in scenarios where a content provider wants to reach many users without overwhelming the network infrastructure.

Understanding multicast is essential for professionals in networking and telecommunications, as it plays a critical role in the performance and scalability of various applications and services.