What are APIs?

If you look up the term API , you'll probably find a number of definitions—some of which are rather difficult to understand. But the key underlying idea is in the name— Application Programming Interface . An API is an interface . It's something that has been created to help two different systems interact with one another.

A key idea to remember is that API functionality is defined independent of the actual implementation of the provider. Essentially, you don't need to understand the entirety of the application implementation in order to interact with it through the API. This has multiple benefits:

1. It doesn't expose the implementation to those who shouldn't have access to it
2. The API provides a standard way of accessing the application
3. It makes it much easier to understand how to access the application's data

Some frequently used APIs include:

• Google Maps API
• Stripe API
• Facebook API
• Instagram API
• Spotify API

If you check out any of the above links, you'll find some extensive documentation for the relevant API. Creating good API documentation is an important consideration all to itself, and we'll be discussing it in some detail later in this course.