Cisco is a provider of switches and routers to commercial consumers. Cisco devices run IOS or NX-OS operating systems. This is a generic tag to be used when no more specific tags are available. See the partial list of tags in the full Tag Wiki.
Since Cisco acquisition of Linksys, the consumer line of switches, firewalls and routers (which do NOT run IOS) have been rebranded under the Cisco name.
This tag is a generic tag - Wherever possible a more specific tag related to the product you are using should be used instead. For example: