An angel investor is an individual who deploys their own capital into startups, typically at the earliest stages before institutional VCs are involved. Angels range from first-time investors writing $5K cheques to experienced operators and former founders writing $250K+ investments and taking active advisory roles. The defining characteristic is that they are investing personal capital rather than a managed fund — their investment criteria, process speed, and follow-on capacity are therefore fundamentally different from institutional investors.
Angel investors are often the first outside capital into a company, filling the gap between founder savings/friends-and-family and the first institutional seed round. Their due diligence processes are typically lighter, their terms are simpler (often just a SAFE), and their decisions can be made in days rather than months. For founders at the idea stage, angels are often the only realistic source of non-dilutive (in the VC sense) early capital.
The best angel investors bring more than capital: they bring networks, pattern recognition, and credibility that helps the company raise its next round. An angel whose name on the cap table opens doors at top seed funds is worth as much as a cheque double the size from an unknown investor. Founders should research angel portfolios and prior involvement as carefully as they would VC track records.