Primary Sector: the sector that includes natural products like agricultural goods (rice, wheat, cotton etc.) produced by exploiting natural resources of earth. Dairy, fishing, forestry and minerals and ores are also natural products and therefore activities involved in attaining those products is Agricultural sector or Primary sector.
Secondary Sector: the sector that includes goods that are transformed from natural products through industrial activities or manufacturing. It includes artificial techniques which change the form of natural products. E.g.: making clothes using cotton fiber from the plant. It is also called Industrial Sector.
Tertiary Sector: the sector that helps in the development of the Primary and Secondary sectors through providing services. Transport, communication, banking, storage, trade etc. all come under Tertiary or service sector. However, it also includes services that doesn’t help directly in producing goods. E.g. education, healthcare, information technologies, network operators etc.