1.Primary sector: . There are many activities that are undertaken by directly using natural resources. . They are called primary since it forms the base for all other products that are subsequently produced. . Since most of the natural products we get are from agriculture, dairy, fishing, forestry, this sector is also called agriculture and related sector. For example: In activities like dairy, we are dependent on the biological process of the animals and availability of fodder, etc. 2.Secondary sector: . It covers activities in which natural products are changed into other forms through ways of manufacturing that we associate with industrial activity. . The product is not produced by nature but has to be made and therefore, some process of manufacturing is essential. . Since this sector gradually becomes associated with the different kinds of industries that come up, it is also called an industrial sector. For example: Using sugarcane as a raw material, we make sugar orgur. 3.Tertiary activities: . These are activities that help in the development of the primary and secondary sectors. . These activities, by themselves, do not produce a good but they are an aid or a support for the production process. . Since these activities generate services rather than goods, the tertiary sector is also called the service sector. For example: Goods that are produced in the primary or secondary sector need to be transported by trucks or trains and then sold in wholesale and retail shops.