What is a network bridge?

A network bridge is a device that connects and joins multiple network segments into one, allowing them to function as a single network. This is essential in networking as it helps to reduce traffic between the segments and improves overall communication efficiency. A bridge operates at the data link layer of the OSI model and uses MAC addresses to determine whether to forward or block data packets, ensuring that only necessary traffic is sent through to each segment.

In contrast, the other options describe different functions. A firewall is designed to monitor and control incoming and outgoing network traffic based on predetermined security rules, while providing internet access involves different hardware or software like routers or modems. Temporary data storage for quick access is the function of cache memory or buffers, not a bridge. Therefore, the defining characteristic of a network bridge is its role in connecting distinct network segments to establish seamless communication.