Delhi sometimes referred to as "Dilli" is the second-largest metropolis in India and the eighth largest metropolis in the world by population.The National Capital Territory of Delhi is spread over an area of 1,484 km and owing to the migration of people from across the country, Delhi has grown to be a cosmopolitan metropolis. Today Delhi is a major cultural, political, and commercial center of India.

Its rapid development and urbanisation, coupled with the relatively high average income of its population, has transformed Delhi. It is the largest commercial center in northern India. Construction, power, telecommunications, health and community services, and real estate form integral parts of Delhi's economy. Delhi has India's largest and one of the fastest growing retail industries as a result, Delhi is currently ranked the 7th most expensive office hotspot in the world.

Delhi's culture has been influenced by its lengthy history and historic association as the capital of India.The Archaeological Survey of India recognises 1200 heritage buildings and 175 monuments in Delhi as national heritage sites. Three World Heritage Sites—the Red Fort, Qutab Minar and Humayun's Tomb—are located in Delhi. Other monuments include the India Gate, the Jantar Mantar, Akshardham and the Bahá'í Lotus Temple are examples of modern architecture. Raj Ghat and associated memorials houses memorials of Mahatma Gandhi and other notable personalities.Other important structures include the Rashtrapati Bhavan, the Secretariat, Rajpath, the Parliament of India and Vijay Chowk.