Service Industry, group of industries involved in providing services, as opposed to primary
industries (such as agriculture and mining) and secondary industries (manufacturing and production). Service industries are commonly known as tertiary industries. The term “services” covers a huge range of economic activities, including retailing, banking, insurance, catering, medicine, law, accountancy, cleaning, teaching, television production, the civil service, sport, transport, and many more activities.
Over the past century the service sector has expanded in the developed world. The service sector is now the most important sector in the advanced economies, accounting for about two thirds of the total economy in countries such as the United Kingdom and the United States.