Which network device translates data from one format to another?

A gateway is a network device specifically designed to act as a "gate" between two networks that use different protocols. By translating data from one format to another, a gateway ensures that communication can occur smoothly between systems that may use different architectures, data formats, or networking protocols. This is crucial in scenarios where devices on one side of the gateway need to connect and communicate effectively with devices on another side that operate quite differently.

In contrast, routers primarily direct data packets between networks but do not convert data formats or protocols; they work mainly on layer 3 of the OSI model, focusing on routing functionalities. Switches operate at layer 2, managing data traffic within a local area network by forwarding packets based on MAC addresses without involving protocol translation. Bridges serve to connect two segments of a network, but their function is more about filtering traffic and reducing collision domains rather than converting data formats. Thus, the gateway stands out as the device that performs the necessary translation of data formats and protocols.