BSB is the IATA code of Brasilia International Airport - President Juscelino Kubitschek, located in Brasília, Federal District. The acronym is also used with the meaning of Brasília, a simplified way of writing the name of the city.
To facilitate the identification of airports around the world, three-letter codes were created by IATA to be used, for example, on airline tickets and on stickers that identify luggage, simplifying processes airports.
The IATA - International Air Transport Association (in English, International Air Transport Association) is one of the entities responsible for assigning the codes that designate the names of airports and airlines.
Some examples of IATA codes:
In Brazil
CWB - Afonso Pena International Airport (Curitiba, Paraná)
gig - Rio de Janeiro International Airport - Antônio Carlos Jobim (Rio de Janeiro)
SSA - Salvador International Airport - Deputy Luís Eduardo Magalhães (Salvador, Bahia)
In other countries
CGD - Paris Airport - Charles de Gaulle (Paris, France)
LIS - Portela Airport (Lisbon, Portugal)
PEK - Beijing International Airport (Beijing, China)
Airport and airline identification codes are also created by the ICAO - International Civil Aviation Organization (in English, International Civil Aviation Organization), however, are composed of four letters.