hub
termnetworking
A repeater that copies every frame to every port - the device switches replaced, and the reason older networks shared bandwidth.
Everything plugged into a hub was in one collision domain and could see everyone else's traffic, which is why packet capture used to be trivial and why switching was a security improvement nobody sold as one. The word survives in two useful places: a port mirror deliberately recreates hub behaviour for monitoring, and wireless is a shared medium by physics, so the old contention arithmetic still applies to a channel even though the cabling stopped working that way decades ago.
Also known as: repeater