
Web Services:
Web services can be explained as application components which communicate using open protocols and are self-contained and self-describing. Web services can be discovered using UDDI (Universal Description Discovery and Integration). It can be used by other applications as well. The foundation for web services is XML (Extensible Markup Language). Simply Web services are Application Programming Interfaces (API) or web APIs that can be accessed over a network, such as the Internet, and executed on a remote system hosting the requested services.
The main motive for using Web services are to gain interoperability among distributed applications that span diverse hardware and software platforms and to gain accessibility of applications through firewalls by using Web protocols.