On the back of your license is either a bar code, or a magnetic stripe. I’ve already written about whats in the drivers license bar code, and will soon be writing about whats in the mag stripe, but this post should help explain what states use bar codes, what states use mag stripes, and what states use both.
Here is a color coded map to show you how the different states encode the information:
As you can see, the vast majority of the states use a bar code to house the data. If you’re looking for more information on this bar code, please read our detailed post on the drivers license bar code.