These are highly skilled, elite "Interagency Hotshot Crews" (IHC). They meet the most arduous physical standards and handle the most complex, high-priority parts of a fire.

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

When talking about "Fire Department (Version 1, 2, & 3)," there are a few different ways this is commonly categorized—it could refer to how are handled, how firefighting teams are built, or even the evolution of LEGO sets . 1. Fire Alarm Levels (1, 2, and 3-Alarm Fires)

If the first responders find the situation more serious, they call for a second alarm. This effectively doubles the resources on-site, bringing in more firefighters and specialized equipment.