What are APIs?
So, without going into the heavy technical aspects, APIs are a way for applications to exchange data and functionality. A good example is a telephone call. Let's imagine that we have Joe and Judith who are best friends and looking to get together to hang out later today. Now, neither one of them has talked yet to see whether the other is available to play, so the first thing they need to do is get in contact with each other.
For them to communicate and make a plan, they need to talk. To do that, Joe calls Judith on her phone. Judith then picks up the phone, recognizing it is Joe, and says hi and waits to hear Joe respond on the other end. After they say their salutations, they work to catch up on how each of them has been doing since the last time they talked. Then, they get to the crux of the call: Joe brings up when Judith will be available to hang out with him at his place. Judith says she is free to come over in 30 minutes. From there, they both say goodbye...