Different Cisco OS

Cisco has a whole bunch of different operating systems for a variety of products:

• IOS runs on most Cisco routers and switches.
• IOS XE is a more modern, modular version of IOS.
• IOS XR runs on high-end routers.
• NX-OS runs on the Nexus line of datacenter switches.
• ASA OS runs on Cisco ASA devices.
• AireOS runs on Access Points.