3 buttons

Could someone explain the meaning of these three buttons? I have a slight understanding of what they do but I’m not entirely sure.

 

From the left.
1. Fog Light
2. Rear Differential Lock
3. Power inverter for the rear outlet in the bed of the truck.

#1- Turns on the Fog Lights. The ones lowest and under the front bumper.

#2 Locks the 2 Rear wheels to gather so that they turn at the same time.
Never use this on pavement or hard surfaces.

#3 Supplies power to the rear outlet in the bed of the truck.
It’s honestly not very good, You are not going to be able to run most power tools.
Think of it as a big charging port for batteries, cell phone, etc.