API's sound scary. It sounds like you need an adult, or maybe a developer. But - you don't. Infact there is a pretty simple tool us muggles can use to build very useful APIs. I'll show you how, but first - what would you use an API for?
An API is something something, super technical blah blah blah. A lazy data journalist might describe it as a bridge or programing language between to data sources or pieces of software.