The ASP.NET Web API services are built on the basic nature of HTTP:
POST. In this way, you can send a request to a service the same way you would type a uniform resource locator (URL) into your browser. This request can pass parameters on the query string. Of course, you can get a response from the service, too. You can also post data to a service, work with Secure Sockets Layer (SSL) for security, and do most of the basic web-like things you would do in any website.
You can add ASP.NET Web API services to any ASP.NET web application. The services can be hosted on the same server and domain as another website. (Of course, there are other hosting options, too.) This means you can define a Web API service ...