Most of it depends on how many companies are called.
Around here its a 1, 3, or 1010.
3 is fire trucks, and fire fighters (in personal cars) race to fires, horns blaring sirens blaring making cars pull over (the fun alarm)
1 is no sirens or alarms. A 3 usually goes to a 1 once two or three companies arrive
10-10 means there is a fire, but disregard it because no more help is needed.
Alarms in places range from 1-4 and 5th alarm is only used in cities. Any more questions...
