Wireless and network types
Access point and controller
The bridge between the air and the wired network, and the box that manages many of them.
An access point announces a network name (SSID) and bridges its wireless clients onto a wired network, like a switch port shared through the air; each radio has its own hardware address (BSSID). A home router is a router, switch and access point in one box; a phone hotspot is the same idea over a mobile line (tethering). Offices run many APs managed by a controller, which pushes one configuration, plans channels and lets a laptop roam from AP to AP without losing its address. Anyone can announce any SSID: a name proves nothing about who runs the network.