What are the basics of APIs?

Application Programming Interfaces (APIs) allow different software systems to communicate with each other. You can think of an API as a set of commands and protocols that developers follow to access functionality or data from another application.

At a high level, here is how APIs work:

1. A company like Twitter or Google provides an API for developers to access parts of their systems in a controlled way.
2. Developers then use the commands and protocols defined in the API to request data or functionality from the company's systems.
3. The company's servers receive the API requests, process them, and return a response. This allows the developer to build applications that leverage the company's capabilities.

For example, the Twitter API allows developers to request a user's last 20 tweets from their Twitter systems. Here is roughly what happens behind the scenes when you load tweets on an app:

1. The app makes a request to the Twitter API to get the last 20 tweets for a user 
2. Twitter's servers receive the request and query the user's tweet data
3. The Twitter API returns a response with the tweet data formatted in JSON
4. The app processes the JSON data and displays the tweets  

So in summary, APIs allow different applications to communicate by defining a common interface with standard inputs and outputs. They abstract away the implementation details of complex systems and only expose carefully selected functionality.

Some key benefits of APIs include:

There are many different types of APIs like REST, SOAP, GraphQL, and more. They follow different styles of architecture and protocols under the hood.

Learning APIs does take practice and patience. Start by finding a public API in an area that interests you and try making basic calls. As you start working with responses and connecting APIs, you'll progressively understand more of the moving pieces.

I hope this high-level introduction helps demystify APIs! They allow developers to stand on the shoulders of giants and are integral to modern software. Feel free to reach out with any other API questions.