I/O Multiplexing is a technique used in computer systems to manage multiple input and output operations simultaneously. It allows a single process to monitor multiple file descriptors, such as sockets or files, to see if they are ready for reading or writing. This is particularly useful in network programming, where a server may need to handle many client connections at once without creating a separate thread for each one. By using I/O Multiplexing, applications can efficiently utilize system resources and improve performance. Common methods for implementing this technique include select, poll, and epoll. These methods help determine which file descriptors are active, enabling the application to respond promptly to events.