An auto mechanic is a mechanic who services and repairs automobiles, sometimes specializing in one or more automobile brands or sometimes working with any brand. In fixing cars, their main role is to diagnose and repair the problem accurately and quickly. Seasoned auto repair shops start with a (Digital) Inspection to determine the vehicle conditions, independent of the customers concern. Based on the concern, the inspection results and preventative maintenance needs, the mechanic/technician returns the findings to the service advisor who then gets approval for any or all of the proposed work. The approved work will be assigned to the mechanic on a work order. Their work may involve the repair of a specific part or the replacement of one or more parts as assemblies. Basic vehicle maintenance is a fundamental part of a mechanic's work in modern industrialized countries, while in others they are only consulted when a vehicle is already showing signs of malfunction. Automotive repair knowledge can be derived from on-the-job training, an apprenticeship program, vocational school or college. Apprentice mechanics work under master mechanics for a specified number of years before they work on their own. Some areas have formal apprenticeship programs, however many automotive repair shops utilize an informal apprenticeship system within their facilities. A master mechanics is often incentivised to train an apprentice by earning additional wages from the work produced by the apprentice. In the United States, many programs and schools offer training for those interested in pursuing competencies as automotive mechanics or technicians. Areas of training include automobile repair and maintenance, collision repair, painting and restoring, electronics, air-conditioning and heating systems, and truck and diesel mechanics. The National Automotive Technicians Education Foundation (NATEF) is responsible for evaluating training programs against standards developed by the automotive industry.