Wheel of Fortune is an American television game show created by Merv Griffin. The show has aired continuously since January 1975. It features a competition in which contestants solve word puzzles, similar to those in Hangman, to win cash and prizes determined by spinning a giant carnival wheel. The network version was originally hosted by Chuck Woolery and Susan Stafford. Woolery left in 1981 and was replaced by Sajak.

Source: Wikipedia