The document discusses the three main economic sectors - primary, secondary, and tertiary. The primary sector involves extraction of raw materials from nature. The secondary sector transforms these raw materials into finished goods through manufacturing. The tertiary sector provides services to support the other two sectors, such as transportation and banking. It notes that historically the primary sector was most important but now the secondary and tertiary sectors contribute more to GDP and employment in developed countries. In India, most employment remains in the primary sector despite it contributing a lower share of GDP. The document also discusses organized vs unorganized sectors and ways to protect workers in the unorganized sector.