What does "duplex" refer to in networking?

Duplex in networking specifically refers to the direction of data transmission between devices. It defines how information is sent and received across a communication channel. In a networking context, there are primarily two types of duplex modes: half-duplex and full-duplex.

In half-duplex mode, data transmission can occur in both directions, but not simultaneously. This means that when one device is sending data, the other must wait until the transmission is complete before it can send its own data. This mode is common in older technologies, like walkie-talkies or some shared network systems.

Full-duplex, on the other hand, allows for simultaneous two-way communication. In this mode, both devices can send and receive data at the same time, greatly improving the efficiency and speed of data communication. Examples of full-duplex communication can be found in modern Ethernet networks, where devices can transmit data back and forth without any waiting.

Understanding duplex is essential for network design and performance, as it can significantly affect data flow and communication efficiency between devices.