Entrepreneurs on Dragon's Den usually offer equity in return for an investor’s money.
Equity means an ownership stake in a company. A contestant may request a specific investment and offer a stated percentage of the business, allowing the investor to share in potential future growth, profits or a later sale.
The negotiations often focus on whether the requested percentage matches the company’s valuation. Investors may offer a different amount of money, seek a larger stake or decline if they believe the risk is too high. A televised offer is not necessarily the same as a completed deal after filming.
Debt is a different type of finance: it normally has to be repaid, while equity gives ownership. Contestants can discuss loans or other arrangements, but the signature Dragon's Den proposal is investment in exchange for equity.