Hair straightening is a hair styling technique used since the 1890's which involves the flattening and straightening of hair in order to give it a smooth, streamlined, and 'sleek' appearance. It was made by Garret A. Morgan, to help African American manage their hair. It became very popular among blacks male and female and females of all races, during the 1950's, because black people wanted to have the very popular and stylish "greaser"look, either that or wearing Afros. It accomplished using a hair iron or hot comb, chemical relaxers, Japanese hair straightening[citation needed], or Brazilian hair straightening. In addition, some shampoos, conditioners, and hair gels can help to make hair temporarily straight. The process is often called "rebonding" in Southeast Asia (e.g. Malaysia and Philippines)

http://en.wikipedia.org/wiki/Hair_straightening