Without that info, I would guess it would be the channel that they use for their operations. Now that could be general operations, or specials circumstances like large scale emergencies, just depends on who is using the channel/TG and how they want to use it.
The ops channels assigned to each agency is for what ever they need it for. Most agencies on the safe-t system are assigned 3 ops channels aside from their main talkgroup.
Many agencies are not using all their ops TG's, but keep them programmed into the scanner, as they may become active at any time.
State Police dist. 13 uses Ops 1 for their car to car chit-chat. Ops 2 is so rarely used, I'm not even sure what it's used for. Ops 3 is used so State Police can talk to the TMC (traffic management center).
That would be their talkgroup on the state system. You would need a scanner capable of digital operations to receive that. I'm sure on of the locals can advice what works better for that system if they have any experience monitoring it.
When Boone County dispatches fire and ems, they send the dispatch on the dispatch channel, and at the end they say "Ems Ops" or for fire, "Fireground 1." This assigns the responders to a specific channel so as not to tie up the net. Then let's say they get ANOTHER fire or medical call during the initial one, they will assign the next crew to "Ops 2" or "fireground 2."
Just a means of organizing the fire and ems crews.