Question

what do you mean by second urbanisation

Answer 1

when the villages change into city or trading town it is called second urbanization

Answer 2

During the time between 800 and 200 BCE the Śramaṇa movement formed, from which originated Jainism and Buddhism. In the same period the first Upanishads were written. After 500 BCE, the so-called "Second urbanisation" started, with new urban settlements arising at the Ganges plain, especially the Central Ganges plain.The foundations for the Second Urbanisation were laid prior to 600 BCE, in the Painted Grey Ware culture of the Ghaggar-Hakra and Upper Ganges Plain; although most PGW sites were small farming villages, "several dozen" PGW sites eventually emerged as relatively large settlements that can be characterized as towns, the largest of which were fortified by ditches or moats and embankments made of piled earth with wooden palisades, albeit smaller and simpler than the elaborately fortified large cities which grew after 600 BCE in the Northern Black Polished Ware culture.The Central Ganges Plain, where Magadha gained prominence, forming the base of the Mauryan Empire, was a distinct cultural area, with new states arising after 500 BCEduring the so-called "Second urbanisation". It was influenced by the Vedic culture,but differed markedly from the Kuru-Panchala region.It "was the area of the earliest known cultivation of rice in South Asia and by 1800 BCE was the location of an advanced Neolithic population associated with the sites of Chirand and Chechar".In this region the Shramanic movements flourished, and Jainism and Buddhism originated.