A mechanic is a person who uses tools to repair things (generally machinery) or works to keep things operating properly.
Many mechanics are specialized in a particular field such as auto mechanics, bicycle mechanics, boiler mechanics, industrial maintenance mechanics (millwrights), air conditioning and refrigeration mechanics, aircraft mechanics, Diesel Mechanics and Tank Mechanics in the armed services. Auto mechanic for example has many trades within. Some may specialize in the electrical aspect, other areas include: brakes and steering, automatic or standard transmission, engine repairs or diagnosing customer complaints. An auto technician has a wide variety of topics to study.