Meaning of city: City is an assembly of such centralised towns in which facilities like developed means of transport and communication, systematic trade centres, administrative units, educational institutions for higher education etc. are available. The density of population is often high in them.
Causes of increasing density of population in cities: Due to industrialization and urbanisation, the density of population is continously increasing in cities. Due to industrialisation, villagers keep on migration to cities in search of jobs and employment. Better living conditions in cities also draw people towards them. That is why the density of population in most of the cities is increasing everyday.