What mode of communication allows data to travel in both directions, but not at the same time?

Half duplex is a mode of communication that supports data transmission in both directions, but only one direction at any given time. This means that while one device is sending data, the other device must wait until that transmission is complete before it can respond or send its own data. An everyday example of half duplex communication is a walkie-talkie; one person speaks while the other listens, and they must take turns to communicate.

This characteristic distinguishes half duplex from full duplex, where simultaneous two-way communication occurs, and simplex, where data can only travel in one direction. Understanding these modes is crucial in telecommunications, especially when designing systems that need to optimize bandwidth and manage device communication effectively.