What is a bridge device and gateway?
A bridge is a hardware device that is used to connect LANs so that they can exchange data. Bridges can work with networks that use different wiring or network protocols, joining two or more LAN segments to from what appears to be a single network.
A bridge operates at the data-link layer of the OSI Model for computer communications. It manages the flow of traffic between the two LANs by reading the address of every packet of data that it receives.
A gateway is a shared connection between a LAN and a larger system, such as a mainframe computer or a large packet-switching network, whose communications protocols are different. It is usually slower than a bridge or router. It is a combination of hardware and software with its own processor and memory used to perform protocol conversions.