Cloud this, virtual that… it’s the future, and mostly it’s a good thing! Welcome to the great WiFi expansion, folks!
Not too long ago, when people started deploying multiple wireless access points (APs) in a single location, they realized how cumbersome it was to manage all APs individually. The masses demanded a way of managing multiple APs from a single location, and so the Controller was born. A Controller is just what the name says: a device that ‘controls’ and manages all APs from one central location.
For some time, this was the only option for managing multiple APs, and there was no way around it. And it was a great thing. It still is.