The document classifies the Indian economy into three sectors based on economic activity: primary, secondary, and tertiary. The primary sector involves agriculture and extraction of natural resources. The secondary sector transforms raw materials into finished goods through manufacturing. The tertiary sector provides services to support the other two sectors. Over time, the share of the primary sector in India's GDP has declined while the tertiary sector has grown significantly, though the primary sector still employs over half of India's workforce due to underemployment. The document also discusses the organized and unorganized sectors based on working conditions and public versus private sectors based on ownership.