Sao Paulo Guarulhos International Airport, located in Sao Paulo, Brazil, is the primary airport for the city and the busiest airport in the country. It is commonly referred to as GRU Airport, after its airport code, GRU. The airport has been in operation since 1985, when it replaced the old Congonhas Airport in Sao Paulo as the main international airport for the city. Prior to its opening, passengers had to travel to Congonhas Airport to catch international flights, which was inconvenient for many travelers.

The name of the airport was chosen to honor the city of Guarulhos, where the airport is located. The city of Guarulhos is located in the state of Sao Paulo, and it is the second largest city in the state. The name was also chosen to reflect the fact that the airport serves not only the city of Sao Paulo, but all of the surrounding cities, towns, and regions as well.

The airport code, GRU, was determined by the International Air Transport Association (IATA). The code is assigned to airports around the world to make them easier to identify and to ensure that each airport has a unique identifier. The GRU code for Sao Paulo Guarulhos International Airport was chosen to reflect the city of Guarulhos, and the letters G, R, and U were chosen to represent the initials of the city.

Sao Paulo Guarulhos International Airport has an average of 1,500 flights a day, including domestic and international flights. Major airlines that serve the airport include American Airlines, Delta Air Lines, United Airlines, Avianca, Copa Airlines, LATAM Airlines, and Azul Brazilian Airlines. The airport also serves several regional airlines, including Azul Linhas Aereas, Gol Transportes Aereos, and TAM Airlines.

Sao Paulo Guarulhos International Airport is an important hub for air travel in Brazil, and it is the busiest airport in the country. It is an important gateway to the city of Sao Paulo and the surrounding area, and it is a major contributor to the local economy.