Each State has different types of state issued ID cards. When purchasing an ID scanner, it is always good to know what kind of IDs you will scan to verify age. Here is a map of the US illustrating the type of ID cards used in each state.
The states shaded in Yellow use PDF417 format, also known as 2D barcode. The barcode looks like a box with black and white speckles. You will need a ID scanner with a 2D barcode reader to check these IDs.
The states shaded in Blue use a magnetic stripe format. The magnetic stripe looks the same as the magnetic strip on the back of a creditcard. You will need an ID checker with a magnetic stripe reader to check these IDs.
The states shaded in Green have both 2D barcode and magnetic stripe on their ID cards. For these IDs, you can use an ID card checker with either a 2D barcode reader or magnetic stripe reader or both.
There are some states with tricky ID cards. Georgia licenses issued before November 2009 are not scannable by any ID checkers. For Michigan, unless scanning the Enhanced Drivers License, the name and address will not be recorded as it is not embedded in the magnetic stripe.
Before purchasing a Drivers License Scanner, it is always a good idea to know what types of ID cards you will be checking and also knowing what types of ID cards are used in the surrounding states.