The U.S. Securities and Exchange Commission (SEC) classifies an accredited investor as an investor who is financially competent and capable of trading securities that aren't regulated.
As a general rule, accredited investors must make at least $200,000 per year in income and/or own at least $1 million in assets.
Once you become an accredited investor, you can purchase unregistered securities --- which are high risk and off-limits to non-accredited investors.