Certified Pre Owned. A 150+ Point inspection is done, more detailed than a pass or fail state and emissions safety inspection. Generally they get new fluids, and wearables like tires and brakes have to be towards the newer side of wear. Provided by manufacturers on newer pre owned cars. Includes an extended powertrain warranty (generally 7 years or 100,000 miles from original purchase date/mileage), includes roadside assistance and some other features depending on the manufacturer.
Certified Pre Owned...previous post is very well written.