Explanation: Agricultural surplus, the growth of crafts and trade, and the growing population led to the emergence of towns in the Gangetic plains.

This is called the second urbanization in Indian history after the first urbanization evident in the Harappan Civilization.

Different types of towns came into being:

• Political and administrative centers such as Rajgriha, Shravasti, Kaushambi and Champa
• Centers of trade and commerce such as Ujjain and Taxila
• Holy centers such as Vaishali.

Source: Tamil Nadu NCERT