Shark Tank is the American adaptation of the investment format behind British Dragons' Den.
The US programme features entrepreneurs presenting businesses to a panel of wealthy investors, who may offer capital in exchange for an ownership stake. Although the title changes from dragons to sharks, the central pitch-and-negotiation structure remains recognisable.
The British programme itself is adapted from the Japanese format Money Tigers. This creates a chain of related versions: Money Tigers provided the original television model, Dragons' Den became the British version, and Shark Tank became the US version.
A common mistake is to call Shark Tank the original programme. It is one of the best-known international adaptations, but it was not the source format. The distinction is useful when tracing how the business-pitch concept travelled between television markets.