Shark Tank is the name of the US television adaptation of the investment format used by Britain's Dragon's Den.
The American series premiered in 2009 and presents entrepreneurs to a panel of investors called Sharks. Like the British programme, it focuses on pitches, valuation, equity negotiations and the possibility that a deal may fall apart during questioning.
The different animal names reflect local branding rather than a completely different concept. British investors are called Dragons, while the US panel is called Sharks. Both series belong to the same broad international television format descended from Japan's Money Tigers.
Shark Tank should not be confused with the British title or with a direct American broadcast of Dragon's Den. It is a separately produced US adaptation, with its own panel, presenters, entrepreneurs and episode history.