What fans are
A device used for cooling themselves down when they feel hot, especially:
1. A machine using an electric motor to rotate vanes in order to move air for cooling.
2. A tool whose shape is usually long triangle or semicircle is made of feathers, leaves, paper, cloth, etc. people usually wave it lightly in a hand to create a cooling current of air.
Various types of fans and their characteristics 
1.Table Fans: small size, appropriate for personal space, cheap price, economical cooling
2.Pedestal Fans: height can be changed, provide powerful air
3.Window Fans: save space, bring in fresh air
4.Wall Mount Fans: save space, offer more air, suit for industrial environment
5.Floor Fans: offer more air, save space, suit for offices and warehouses
6.Tower Fans: small space, vertical shape, quiet
7.Ceiling Fans: on the ceiling, have a lot of styles to match room's decoration
8.Box Fans: flexible, suit for various need of rooms
9.Misting Fans: suit for outside areas
10.Industrial Fans and Blowers: made of durable metal or steel
11.Decorative Fans: has a lot of different styles
12.Bathroom Exhaust Fans: used in bathroom, prevent from excess moisture
origination of fans
The fans making history are at least 3000 years, and the earliest fans can date from 3000 BC according to the record. Fans originated in China. The first European folding fans were brought into Europe by businessman and religious orders from China, and they are considered as a status symbol in Europe then.