Urbanizationimplies the existence of an ordered society with a defined social hierarchy.It also implies the existence of professions other than agriculture which were well organized and employed people with specific skills who could contribute to mass production activities. Since agriculture is not the sole occupation of people, it means that they had more opportunities for employment and could enjoy many comforts not available to an agricultural society. The city or town which is a manifestation of the urban phenomenon in history, has other characteristics which is the outcome of planning- the standardization of building materials (brick sizes), a specific layout of structures (grid planning) and efficient modes of transportation within the city (roads) and communication (a language).

Excavations carried out by the British, Indian and Pakistaniarchaeologists have unearthed enough material evidence from sites scattered over present day India and Pakistan- Mohenjo Daro, Harappa & Ghanweriwala (all in Pakistan), Rakhigarhi, Dholavira, Kirsara & Lothal (all in India), to name a few. Evidence of town planning as described above and the use of bricks of specific sizes, pottery, beads, weapons & seals, all these suggest that the sites could support large populations, whose workforce were probably organized into guilds representing those who belonged to specific professions and occupied specific quarters within the city. The sites procured food from outside the city limits where agricultural communities resided.The seals excavated from these sites seem to indicate the presence of a language which awaits decipherment.

Based on the available evidence as of today,the sites associated with the Harappan culture marks the first phase of urbanization in the sub-continent and are associated with the Bronze Age.