What is an accredited investor?

In the United States, to be considered an accredited investor, one must have a net worth of at least $1,000,000, excluding the value of one's primary residence, or an income of at least $200,000 each year for the previous two years (or $300,000 combined income if married) and have the expectation to make the same amount this year.

You may also invest as an entity (LLC, Partnership, C-corp, etc.) if your entity meets certain requirements. The SEC provides specific guidance here.