Slot cars are miniature vehicles that are powered by electricity and run on a track. They are usually raced against each other, and the term 'slot car' refers to the slot in the track that the car fits into. The most common type of slot car is a RACER, which is a small car with a motor and guide pin that fits into the slot in the track. Racers come in a variety of sizes and styles, and can be used for both competitive and recreational racing.