API examples are littered throughout your everyday life, whether you know it or not. This is because APIs are the primary software infrastructure ensuring that distinct software can work in unison.
Examples include:
https://www.trio.dev/blog/api-examples
APIs are mechanisms that enable two software components to communicate with each other using a set of definitions and protocols. For example, the weather bureau's software system contains daily weather data. The weather app on your phone “talks” to this system via APIs and shows you daily weather updates on your phone.