what is the difference between Deg and Rad?

They are both units that are used to measure angles.

1 revolution is 360°

or

1 revolution is  $$2\pi$$      (If there are no units displayed then you are supposed to assume that it is radians)

Although I was taught to use a little superscript c for radians (and it is still acceptable)

 

So I might write   $$180^0=\pi^c$$