The term ‘population’ refers to the number of people living in a defined area. The statistical study of the characteristics of human population is called demography.
Coimbatore, Chennai, Tiruvallur, Kancheepuram, Villupuram, Dharmapuri, Salem, Madurai and Tirunelveli are the most populous districts in the state. Agriculture and industrial development are the main causes of high concentration of population of these districts.
Tiruvannamalai, Cuddalore, Tiruchirapalli and Thanjavur districts have a population 30– 35 lakh. Vellore, Dindugal, Virudhunagar and Thoothukudi districts each have a population of 15–20 lakh. Other than agriculture, small-scale industries and fishing along the coastal areas are the major occupations of people in these districts.
The coastal districts Nagapattinam, Tiruvarur, Pudukottai, Ramanathapuram and Sivagangai have a less than 15 lakh. The Nilgiris district has a population of less than 10 lakh population.
The state ranks 12th among the Indian states in population density. The national average density of population as per the 2011 Census is 382. Chennai is the densest district with 26,903 persons per sq.km followed by Kanyakumari, Tiruvallur, Kancheepuram,
Madurai, Coimbatore, Cuddalore, Thanjavur, Nagapattinam, Salem, Vellore and Tiruchirappalli. These are the regions with high density of population. The least density of population is recorded in the Nilgiris and the other districts have moderate density of population.
Hinduism, Christianity and Islam are the major religions in the state. The Hindus constitute the largest of the population, followed by Christians and Muslims. Jainism, Sikhism and Buddhism and people of other religions also presence in the state.
The sex ratio represents the number of females per 1000 males.
The highest sex ratio is found in the Nilgiris district followed by Thanjavur district. The lowest sex ratio is reported in Dharmapuri district followed by Salem district.
The district of Kanyakumari has reported the highest literacy rate while Dharmapuri district has the lowest rate. A high level of literacy rate is also seen in Chennai, Thoothukudi, the Nilgiris and Kancheepuram districts.