Active Hub:
A central device to which other devices connect, and which not only forwards signals, but also amplifies or refreshes the stream of data, which otherwise would deteriorate over a long distance.An active hub is also called a repeater.

Passive Hub:
A central device to which other devices connect, and which forwards signals.A passive hub can be used to connect several computers together in a star configuration; it does not regenerate signals or process them in any way.

Intelligent Hub:
A central connecting device in a network that provides intelligent functions as well as forwarding signals.An intelligent hub can provide bridging, routing and switching, and even more complex functions such as network management and LAN emulation.