Web Services - Components.
Web service architecture identifies three types of component, the service provider, service client and service registry. Communications between components is based on XML messaging. The web service components are described in the following sub-sections.
Service Provider (or Server)
The service provider implements the server side of the client/server interface. It provides a service to its clients. The services are published within the registry.
The service client makes use of the service. It implements the client side of the client server interface. It uses the registry to discover a service and its description.
The registry is a network server that maintains details of available services. The registry data is provided by the service providers and queried by the service clients.