Elements of a Web Service

Interface definition
WSDL - Web Service description language.
- WSDL defines the interface of s particular web service.
- ie: Methods, return values, parameters, datatypes etc
Also describe the bindings of a web service.
- URL to find the web service at.
- Supported protocols to use for communication.
- Supported message formats.

Communication protocol
Almost universally HTTP, but doesn't have to be.

Message formats
SOAP 1.1, SOAP 1.2 or even CGI POST

Web Server (for hosting the web service)
.NET needs Microsoft's internet information server (IIS), although Mono is extending this to other web servers.