Shark Tank is the United States television adaptation of the business-pitch format associated with Britain's Dragon's Den.
In Shark Tank, entrepreneurs present companies and products to a panel of investors known as sharks. As in Dragon's Den, the contestants generally seek investment in exchange for an ownership stake, and the discussion centres on sales, valuation, margins and growth prospects.
The two programmes are not unrelated inventions: both descend from the Japanese format Money Tigers. Their shared structure is why the British investors are called dragons while the American investors are called sharks.
A common mistake is to describe Shark Tank as a remake of a single British series. More precisely, both are national adaptations of the same Japanese-origin format, with local presenters, investors and production histories.