There are many properties defined in the WebServices class:
Application - Obtains the application object for the current HTTP request
Context - Obtains the HttpContext object for the current request, which encapsulates all HTTP-specific context used by the HTTP server to process Web requests
Server - Obtains the HttpServerUtility object for the current request
Session - Obtains the HttpSessionState object for the current request
SoapVersion - Obtains the version of the SOAP protocol used to make the SOAP request to a Web service
User - Obtains the Server User Object. This property can be used to authenticate whether a user is authorized to execute the request.