Web Services is a mechanism to provide a standard means of communication between various applications operating on similar or heterogeneous platforms. The World Wide Web Consortium (W3C) is the official body for maintaining web services standards.
In the context of Service Oriented Architecture, Web Services are used to facilitate communication between service providers and service consumers. Special adapters are used for applications that don’t support web services.
Krawler employs web services standards that enable our Service Oriented Architecture to offer functionalities such as location neutrality and technology/platform independence.
There are many web services standards used in the SOA framework, including WS-Security, WS-Transaction, WS-Reliable Messaging and WS-Policy. But the underlying principals of web services are publication, discovery and communication:
Publish – Service Producers register their service in the SOA registry. Web Services Description Language (WSDL) is used to describe a service.
Discovery – Service Consumers make a request for a service in the SOA registry. Universal Description, Discovery and Integration (UDDI) standard is used for locating a service in the registry.
Communication – Simple Object Access Protocol (SOAP) is used for facilitating communication between Service Providers and Consumers.
In conclusion, we can say that web services standards provide an open standards based communication framework that operates within the purview of W3C guidelines. Web Services provide a platform/technology independent communication methodology while SOA is an overall IT strategy framework that aims to provide business agility.