A mechanic is a skilled tradesperson who uses tools to build, maintain, or repair machinery, especially cars. Formerly, the term meant any member of the handicraft trades, but by the early 20th century, it had come to mean one who works with machinery, with the rise of the automobile. Most mechanics specialize in a particular field, such as auto body mechanics, diesel mechanics, air conditioning and refrigeration mechanics, auto mechanics, bicycle mechanics, boiler mechanics, race car mechanics, aircraft mechanics, and other areas.

Source: Wikipedia