When your business is very young, raising a seed financing ($50K-$500K) via convertible debt is a great alternative to selling equity. Convertible debt is also known as a bridge loan since it ‘bridges’ the company to its next financing.
Convertible debt (debt for short) is not like getting a loan from a bank. A bank expects to get its loan back. With convertible debt, the lender and your company both expect to convert the debt into equity when you close the Series A. Read Yokum Taku’s series on convertible debt for a primer on this lovely financial instrument.