Shark Tank is the name of the US television adaptation of the UK business show Dragon's Den.
The American programme uses the same broad premise: entrepreneurs present businesses to a panel of wealthy investors and seek funding in exchange for an ownership stake. The animal imagery changes from British “Dragons” to American “sharks,” producing the different title.
Shark Tank premiered in the United States in 2009 and became a major business-reality programme in its own right. Its panel has included investors such as Mark Cuban, Barbara Corcoran and Kevin O'Leary, although the cast has changed across seasons.
Dragon's Den and Shark Tank are related formats, not two names for the same national programme. The British version remains a BBC series, while Shark Tank is the US adaptation broadcast by ABC.