This is the 3799th most frequent Russian word.
airlines
The Russian word for "airlines" is "авиакомпания," which means a company that provides air transportation services.
Here 'авиакомпании' is used in the possessive form, indicating ownership of the flight tickets.
Билеты на рейс этой авиакомпании были дешевле, чем у других.
Tickets for this airline's flight were cheaper than others.
The phrase 'Международные авиакомпании' refers to airlines operating on an international scale, indicating a broader category.
Международные авиакомпании сталкиваются с новыми правилами.
International airlines face new regulations.
In this sentence, 'авиакомпания' (airline) refers to a company or business entity that operates air travel services.