Question about airports (White Giant)

Recently an airport showed up in one of my countries.

It wasn't military related at all....it was just an airport and shows up in a completely different category when I look at "changing icons."

Recently, I also built an Air transport corp in this country? Does this have anything to do with the new airport? What use does this type of airport provide?

Air transport corps = Airports

Airports help your buisness index aswell as immigration into your country. Obviously, they can make you money too, but not as much as other types of corps.