Airports can cater to different aircraft and below is a list of airports by type. Not all airports are like the commercial ones you are used to visiting when travelling around the world. There are many smaller versions of these in the small towns.
Then you can have other types for helicopters, known as heliports, and many of these are for private locations or places like hospitals. The there are the others for seaplanes that are obviously very different again.
The one similarity of all these airports is that they have consistent ways to contact them, refer to them by codes and even locate them using the longitude and latitude coordinates rather than a traditional address.