A bicycle, also called a cycle or bike , is a human-powered , pedal-driven ,
single-track vehicle , having two
wheels attached to a frame , one behind the other. A bicycle rider is called a cyclist , or bicyclist.
Bicycles were introduced in the 19th century in Europe and as of 2003, more than 1 billion have been produced worldwide, twice as many as the number of automobiles that have been produced.[2] They are the principal means of transportation in many regions. They also provide a popular form of recreation, and have been adapted for use as children’s toys, general fitness, military and police applications, courier services,
bicycle racing and bicycle