Shark Tank is the American adaptation of the Dragons' Den business-pitch format.
The American series premiered in 2009 and uses the same broad premise: entrepreneurs present businesses to a panel of wealthy investors and seek capital in exchange for equity. The investors are called Sharks rather than Dragons, giving the programme a distinct title and identity while preserving the negotiation-based structure.
Dragons' Den itself originated from the Japanese format Money Tigers. The concept has been licensed and adapted in many territories, so Shark Tank and the British programme are related versions rather than completely unrelated shows.
A frequent mistake is to treat “Shark Tank” as the original name of the format. It is the United States version. The British series began in 2005, several years before Shark Tank first appeared on American television.