Learn in the textbookConnecting Devices That Make Up a Network
DefinitionA hub (ハブ) is a concentrator that gathers cables from several devices in one place and repeats a signal received on one port out of every other port unchanged.
ExplanationA port (ポート) is the socket on a device where a cable plugs in. A hub does not check where a signal is headed, so even traffic meant for one machine reaches every connected device. The more devices send at the same time, the more often signals run into each other in a collision (衝突), and efficiency drops.
AnalogyIt is like a building's PA system. Even a page for one person is heard by everyone on the floor.
Memory hookA hub is the center of a wheel. The spokes radiating from it match the way cables spread out from a hub.