system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:What is "bridge mode" on a router, and when it is useful?
gpt
It can mean different things. A home router is often a router and a modem combined, but the router part tends to be pretty crappy.

Bridge mode basically disables the router part, allowing you to use the modem to connect a second device directly to the Internet.

The downside is that you can only connect one device this way (usually). Hence, it is usually used to connect a second, better router. The upside is that the slow and buggy built-in router goes out of the way.

Then there's also bridge in the context of WiFi, which was already explained.