Do you know name of device to plug into car computer to diadnose?

Question

I saw the ad on TV it plugs into the car computer system and reads and explains codes.

Answer 1

There are scan tools that have the library of code definition store in its memory, then there are scan tools that just read codes, There are even APP that you can download into you phone that will read codes from a code reading device plug into you vehicle DLC (diagnostic code reader) They can either work by (provided your phone or tablet or even computer)  has blue tooth or even some that uses wifi or cable. There car MD, there Autel, there the Elm products there a variety out there