Population is divided into two parts - rural and urban on the basis of the size and occupation of settlements. The rural population consists of small sized settlements scattered over the countryside.
Urban population is one that lives in large size settlements i.e. towns and cities. However, more importantly this division is based on occupational structure. In India, rural area is defined as one where three-fourths or more of its population is engaged in primary occupations such as farming, animal rearing, forestry, fishing, quarrying, etc.
On the other hand, urban area is one where three-fourths or above of its population is engaged in non-agricultural activities such as manufacturing, trade, transport, communication, banking and social services like health, education, administration, etc.
The total population of India spreads over more than 5.8 lakhs of villages and 4,615 towns. India, proverbially, is considered to be a country of villages. Even today, about 72% of the total population of India lives in villages. But the proportion of rural population has been decreasing in each successive census. Consequently the proportion of urban population to total population has been increasing slowly but steadily. It was as low as 10.8% in 1901 and rose to 27.8 by 2001.
The question arises why is it so? It is because the rate of growth of urban population is higher than that of rural population. In contrast to an average growth rate of about 21.34% in 2001 the urban population has registered a growth rate of 31.13 percent. However all this growth is not a result of only the natural increase of population. In fact, much of the growth of urban population is due to high rate of migration of people from rural to urban areas.
Rural to urban migration also indicates a slow change in the occupations of people from primary to secondary and tertiary activities. Very often limits of municipal or city Corporation areas are extended to cover neighbouring villages or suburbs.
Half of the total urban population of India lives only in five states. These five states are Maharashtra, Uttar Pradesh, Tamil Nadu, West Bengal and Andhra Pradesh. Gujarat, Karnataka, Madhya Pradesh, Bihar, Rajasthan and Union Territory of Delhi, have about 32 per cent of urban population of the country. Rest of the urban population (about 18%) is spread over the remaining states and Union Territories.
According to 2001 census, 35 cities have more than 1000000 population each. They are called the metropolitan or million plus cities. These 35 metropolitan cities alone account for 37.8% of the total population. If this trend continues, India will have more than 50 metropolitan cities in India at the time of 2011and will have half of the urban population of the country. This highly rapid growth of metropolitan cities will brings several problems like supply of housing, electricity, water, school, dispensaries, ration shops, etc.
All the 35 metropolitan cities are arranged in terms of descending orders of population. These are Greater Mumbai, Kolkata, Delhi, Chennai, Bangalore, Hyderabad, Ahmedabad, Pune, Surat, Kanpur, Jaipur, Lucknow, Nagpur, Patna, Indore, Vadodara, Bhopal, Coimbatore, Ludhiana, Kochi, Vishakhapatnam, Agra, Varanasi, Madurai, Meerut, Nasik, Jabalpur, Jamshedpur, Asansol, Dhanbad, Faridabad, Allahabad, Amritsar, Vijaywada and Rajkot.