Pneumatic tools, as in nail guns, mechanic tools like impact wrenches among many others will not operate without compressed air. It also save on an electric bill since the tanks store air. Go ahead and try using a hand to inflate a tire on a car, tractor ect ect... It's a item of convience.

Make sure you consider a name brand air compressor (so you can always get parts) with an electric motor.

Benefits?

Very handy things to have if you need compressed air.

To inflate tires.

Run air powered tools

Spray paint etc

They let you fill up tires with air, air dust things, air dry things, and any other bizarre creation you can come up with plastic tubes and paintballs :)

you don't have to go to the gas station to put air it your tires.

I give up- what?