A qualified institutional buyer (QIBs), as defined by the Securities and Exchange Commission's (SEC) Rule 501 of Regulation D, is an institution, either foreign or domestic, that owns and invests a minimum of $100 million in securities on a discretionary basis (in comparison, the broker-dealer threshold is $10 million). Individuals, regardless of their wealth level or financial sophistication, can't be QIBs.
An accredited investor, as defined by the SEC's (SEC) Rule 501 of Regulation D, is a person or entity that can deal with securities not registered with financial authorities by satisfying one of the requirements regarding income, net worth, asset size, governance status or professional experience. To be considered an accredited investor, you must have earned income that exceeded $200,000 (or $300,000 together with a spouse) in each of the prior two years, and reasonably expects the same for the current year, OR have a net worth over $1 million, either alone or together with your spouse (excluding the value of the person's primary residence).