The "Big Four" professional services and consulting networks comprise Deloitte, PricewaterhouseCoopers (PwC), Ernst & Young (EY), and Klynveld Peat Marwick Goerdeler (KPMG). These colossal global firms dominate the international accounting, audit, tax advisory, and management consulting sectors, providing comprehensive professional services to multinational corporations, governments, and financial institutions across virtually every country in the world.