Created by Rowntree's of York, United Kingdom, Kit Kat is a chocolate-covered wafer bar confection and is now produced globally by Nestlé (which acquired Rowntree's in 1988), except in the United States, where it is made under license by the H. B. Reese Candy Company, a division of the Hershey Company.

The standard bars consist of two or four pieces composed of three layers of wafer, separated and covered by an outer layer of chocolate. Each finger can be snapped from the bar separately. There are many flavors of Kit Kat, including milk, white, and dark chocolate.

The original four-finger version of the bar was developed after a worker at Rowntree's York factory put a suggestion in the recommendation box for a chocolate bar that a man could take to work in his pack. Launched in September 1935 in the UK as Rowntree's Chocolate Crisp, and the later two-finger version was launched in 1936. It was renamed Kit Kat Chocolate Crisp in 1937. Since 1957, the slogan for the Kit Kat in the UK and elsewhere has been "Have a break... have a Kit Kat". Since 1986 in the U.S., the jingle used in television advertisements has been "Gimme a break, gimme a break....break me off a piece of that Kit Kat bar!"

A study at the University of Cincinnati found that Kit Kat's 1986 "Gimme A Break" commercial frequently gets stuck in listeners' heads. The iconic campaign gained fans around the world. Now, New Zealand's 12-finger Kit Kat bars allow for 11 breaks in a single block!

More Info: en.wikipedia.org