Building a Basic Web API
A web API is just an application programming interface (API) over the web (that is, HTTP). When the resources of an application can be manipulated over HTTP using the standard HTTP methods of GET, POST, PUT, and DELETE, you can say that the application supports a web API for other applications to use. Because HTTP is platform-agnostic, HTTP services can be consumed by disparate devices across different platforms.
A central concept of HTTP services is the existence of resources that can be identified through a uniform resource identifier (URI). If you equate resources to nouns, then actions on a resource can ...