A bicycle is a machine having one front and one back wheel attached to a frame. It is a pedal driven machine and is run by humans so we can also call it human powered machine. It is also referred as bike, pushbike, cycle and pedal bike. The person running it is called cyclist or bicyclist.
It is used for travelling but can also be used as a toy for children and for fitness purposes which is most popular now a days. This mechanically-propelled, two-wheeled vehicle (Bicycle) was invented in 19th century by the German Baron Karl von Drais and the first model was called dandy horse or Draisienne or laufmaschine.