A blowdryer or hair dryer is an electromechanical device designed to blow normal or hot air over damp hair, in order to accelerate the evaporation of water particles and dry the hair. Blowdryers allow better control over the shape and style of hair, by accelerating and controlling the formation of temporary hydrogen bonds inside each strand. These hydrogen bonds are very powerful (allowing for stronger hair shaping than even the sulfur bonds formed by permanent waving products), but are temporary and extremely vulnerable to humidity. They disappear with a single washing of the hair.
Hairstyles using blowdryers usually have volume and discipline, which can be further improved by the use of styling products and hairbrushes during drying to add tension, hold and lift.
Blowdryers were invented around the end of the 19th century. The first model was created by Alexander F. "Beau" Godefroy in his salon in France in 1890. The handheld, household hair-dryer first appeared in 1920. Blowdryers are used both in the beauty salon by professional stylists, and in the average household by consumers.