All types of services are special skills provided in exchange of payments. Health, education, law, governance and recreation etc. require professional skills. These services require other theoretical knowledge and practical training. Tertiary activities are related to the service sector. Manpower is an important component of the service sector as most of the tertiary activities are performed by skilled labour, professionally trained experts and consultants.
In a developed economy, the majority of workers get employment in tertiary activity and a moderate proportion is employed in the secondary sector.
Tertiary activities, therefore, involve the commercial output of services rather than the production of tangible goods.