Twix Bars haven't always been known as Twix Bars. In fact, before 1991, they were actually known as "Raiders".
Twix is a chocolate bar made by Mars, Inc., consisting of a biscuit ("cookie" in North America) applied with other confectionery toppings and coatings (most frequently caramel and milk chocolate). Twix are packaged with two or four bars in a wrapper. Miniature and other variations of Twix bars are also available.
The product was first produced in the United Kingdom in 1967 and introduced in the United States in 1979. Twix was called Raider in mainland Europe for many years before its name was changed in 1991 (2000 in Denmark, Finland, Norway, Sweden, and Turkey) to match the international brand name. The name Twix is a portmanteau derived from "twin biscuit sticks".
In 2014, the company introduced Twix bites.