Indira Gandhi Airport has two active passenger terminals: Terminal 1 and Terminal 3.
Terminal 1, is used by low cost carriers such as GoAir, IndiGo and SpiceJet, and is divided in Terminal 1-C, used for domestic arrivals, and Terminal 1-D, used for departures, it can handle 10 million passengers annually.
Terminal 3 is the newest terminal, it was opened in 2010 and is one of the biggest terminals in the world, being able to handle 40 million passengers per year. Other terminals like T1A, T1B, T2 are unused nowadays.
All International flights are operated from T3, Domestic Flights are operated in T1 or T3, depending of the Carrier. Lowcost Carriers (GoAir, IndiGo and SpiceJet) are operated from Terminal 1, while the other carriers are operated from T3. Check below some information you must now of both terminals.