When we say "City" and "County", we're not referring to what agencies are on the system, but who the frequencies are licensed to and which jurisdiction maintains the system.
Thus, the
"City" system is the one that Sac City PD, West Sac PD, and West Sac Fire are all on.
The
"County" system is the one that the Sheriff, Sac Metro Fire, and Sac City Fire are all on.
Obviously, there are MANY more users than just these, but they're the major players. I also hyperlinked the database for the systems.