list the two urbanizations that took place in ancient india.

 urbanisation in ancient India had two distinct phases. The first phase characterised by the emergence of Harappan cities which collapsed after about 600 years without leaving any surviving urban centres. It was only after another thousand years or so that we find towns emerging in ancient India for the second time.The second phase of urbanisation emerged and flourished in an altogether new socioeconomic milieu generated by the widespread use of iron technology.