web services are mechanism to acess remote programmeble logical unit by using http and xml combinly called SOAP(simple object access protocol)

Soap has some methods to access programmeble application logic by get, and post method.

a client of web services has nothing to do with the internal logic of web services.

they only have to know how to send and get for xml request ie SOAP. while

web applications are accessible by clients and they are boud with assemblies.