The most common way people distinguish "versions" of fire department activity is by the assigned to an emergency. This dictates how many resources and personnel are sent to the scene.
If you are looking at the "versions" of the throughout history, the community often groups them by their design evolution. CAL FIRE/San Diego County Fire - Facebook Fire Department (version 1 & 2 & 3)
In wildland firefighting (like forest fires), crews are strictly typed by their skill levels and capabilities. The most common way people distinguish "versions" of
