The three-sector theory is an economictheory which divides economies into three sectors of activity: extraction of raw materials (primary), manufacturing (secondary), and services (tertiary). It was developed by Colin Clark and Jean Fourastié. According to the theory, the main focus of aneconomy's activity shifts from the primary, through the secondary and finally to the tertiary sector. Fourastié saw the process as essentially positive, and in The Great Hope of the Twentieth Century he writes of the increase inquality of life, social security, blossoming of education and culture, higher level of qualifications, humanisation of work, and avoidance ofunemployment.
Countries with a low per capita income are in an early state of development; the main part of their national income is achieved through production in the primary sector. Countries in a more advanced state of development, with a medium national income, generate their income mostly in the secondary sector. In highly developed countries with a high income, the tertiary sector dominates the total output of the economy. PRIMARY SECTOR OF INDIAN ECONOMY
The Primary sector of the economy is the change of natural resources into primary products. Most products from this sector provides raw materials for other industries. The share of primary sector has decreased from the past four decades. In 1970 the share of the sector was 50% which has reduced to 29% in 1995 and is now further reduced to 25%. Major businesses in this sector are agriculture, agribusiness, fishing,forestry, all mining and quarrying industries.
Agriculture
Agriculture in India is the major sector of its economy. Almost two-thirds of the total work-force earns their livelihood though farming and other allied sectors like forestry, logging and fishing which account 18% of the GDP. These sectors provide employment to 60% of the country’s total population. About 43% of the country’s total geographical area