Snickers is a brand name candy bar made by Mars, Incorporated. It consists of nougat topped with caramel and peanuts, enrobed in milk chocolate.  Snickers has annual global sales of $2 billion.

In the United Kingdom and Ireland, Snickers was formerly sold under the brand name Marathon until 1990.   More recently, Snickers Marathon branded energy bars have been sold in some markets.

Info gleaned from Wikipedia