(i) Tertiary activities are related to the service sector. Man power is an important component of the service sector as most of the tertiary activities are completed by skilled labour, professionally trained experts and consultants. (ii) These activities include both production and exchange. The production involves the provision of services that arc consumed whereas exchange involves trade, transport and communication facilities that are used to overcome distance. (iii) Tertiary activities involve the commercial output of services rather than the production of tangible goods. Not directly involved in the processing of physical raw materials—work of a plumber, electrician, technician, launderer, barber, shopkeeper, driver, teacher etc.