Criteria for what constitutes a family business have shifted over the years, focusing on the degree to which two or more family members are involved with ownership, management, or control of a privately- or publicly-held business. Although a business may have family members in management or operational positions, family participation in ownership and/or control is required for it to be called a family business.  Some definitions require family ownership to be at least 50%, i.e., majority-owned, but this is not universally accepted, particularly in publicly held companies. Majority family control in terms of ownership percentage or voting share class is more commonly required.

The majority of businesses across the globe are family businesses. However, many of these are small local operations. “Family business” is not synonymous with family enterprise, which involves a greater span of financial, legal, and family entities that may include various governance structures, a family office, a family foundation, boards of directors, and multiple family members who may or may not have ownership or work in the business. Although many family enterprises began with or still have a family business, a current ongoing family-owned or -controlled operating company is not a requirement in a family enterprise.