A pre-purchase inspection is an independent, third-party professional service that evaluates a vehicles condition before a purchase offer is made. Consumer protection organizations such as the Federal Trade Commission, the American Bar Association, insurance companies, and states recommend an independent pre-purchase inspection. The prospective buyer hires a qualified evaluator who examines the target vehicle for defects, hidden damage, maintenance history, and safety, then typically provides a written evaluation report. The service results in factual information that the prospective buyer uses as decision support for the vehicle purchase. Unless the vehicle is unsafe to drive, the evaluator does not provide a purchase recommendation.
Source: https://en.wikipedia.org/wiki/Pre-purchase_inspection