The document defines and compares different types of family offices: - Mainstream family offices serve more than one family group and provide similar services to single-family offices at a lower entry level of $25-50 million in assets. - Single-family offices serve a specific family group, generally with over $100 million in investable assets. - Virtual family offices offer website-based services for family wealth management and governance starting at $10 million in assets. - Administrative, comprehensive, and hybrid family offices are differentiated by the services they provide, such as bookkeeping, advisory, and outsourcing non-strategic functions.