Cycling, also known as cycling or cycling, refers to the use of bicycles for transportation, entertainment, sports or sports. Cyclists are known as "cyclists," "cyclists," or, less commonly, "cyclists.". In addition to two wheeled bicycles, "cycling" also includes the cycling of unicycles, tricycles, four wheeled vehicles, horizontal and similar human powered vehicles (HPVs).

Bicycles came out in the 19th century, and now there are about one billion bicycles around the world. They are the main means of transport in many parts of the world.

Cycling is generally considered as a very effective means of transportation, suitable for short to medium distance riding.

Compared with motor vehicles, bicycles have many advantages, including continuous physical exercise during cycling, easier parking, greater mobility and access to roads, bicycle lanes and rural trails. Cycling can also reduce fossil fuel consumption, reduce air or noise pollution, and greatly reduce traffic congestion. These result in less financial costs for users and society as a whole (negligible damage to the road, small road area required). By installing bicycle frames at the front of the bus, the bus organization can significantly increase the service scope.

One of the disadvantages of cycling is that bicycles (except tricycles or four-wheel vehicles) must be balanced by cyclists to keep upright. Compared with motor vehicles, the protection ability in collision is reduced, and it usually takes longer driving time (except in densely populated areas) , the fragility of weather conditions, the difficulty of transporting passengers and the basic fitness level required for medium and long-distance cycling.