Activities can be classified under the following three sectors on the basis of their nature of their products or materials used :
(i) Primary Sector: Activities concerned with collecting or making available materials provided by nature are included in the primary sector. Some such activities are (a) Agriculture; (b) forestry; (c) animal husbandry; (d) poultry farming; (e) finishing and (f) mining.
(ii) Secondary Sector: Such act ivies which transform raw materials or primary products into commodities more useful man are included in the secondary sector. Some such activities are (a) manufacturing and (b) quarrying.
(iii) Tertiary Sector: This sector included those activities which are a must for running modern industries in a big way. Some such activities are (a) trade; (b) transport; (c) communication; (d) banking; (e) health; (f) education; (g) insurance; (h) tourism and (i) various other services .