Does one needs a WebServer to have a WebSErvice running?

[Guest]

Hello I am new to WebServices.
I realize WebServices utilizes HTTP and XML. I realize that user can invoke
webservice via WebBrowser (One possible way). But is it necessary to have
WebServer running. Can't the Browser point to the URI and have the SoapListener
listening on a particular port ?

Any help or direction is greatly appreciated.