what is the difference between a use care a certified car

Restate the question.

A certified used car is one that, supposedly, has been checked over by the Dealer's service department and has passed a checklist to make sure it's in good condition. Age, mileage, no accidents (usually), didn't come from the auction (usually), no branded title, and several mechanical components are supposed to be checked. Brakes, tires, drives fine, no leaks, transmission shifts good, no check engine light problems, battery condition, and probably other things too. A non certified used car is just cleaned and detailed, then put on the lot for sale. These are usually older models from a little used car lot that probably came from the auction and God knows what's wrong with it! Jim