Answer by Ron Savage for what is API web services, how do you create them and why?

Answer by Ron Savage for what is API web services, how do you create them and why?:
A web service is a type of program running on a web server built especially for other programs to use, by submitting information requests to it in a particular format (usually some information wrapped in XML).

The API part (Application Programming Interface) is usually a class or set of classes that have the code that knows how to format the information to make requests from the Web Service - so that your program only needs to make the usual function calls to the API classes.

It simplifies your use of the web service.

Here is an example of how to make one, and use it for .NET languages: http://www.codeproject.com/KB/XML/BeginnerWebService.aspx

Any program that uses the web for its interface is a web application, like this site or Facebook.

An Application Service Provider is a company that helps you write web apps (http://en.wikipedia.org/wiki/Application_service_provider) or provide other services.