The Cisco Supervisor Engine is the brain of many of Cisco's switches. The Supervisor Engine has evolved several times. While it is the management segment of many routers, the power of the switch is often much greater than that of the Supervisor Engine because one of the features of many switches is that dozens of the functions are accelerated by ASIC chips.
Abridged list of features:
References
Supervisor Engine (Cisco) Wikipedia(Text) CC BY-SA