By using Web services, your application can publish its function or message to the rest of the world.
Web services use XML to code and to decode data, and SOAP (Simple Object Access Protocol) to transport it (using open protocols).
SOAP is versatile enough to allow for the use of different transport protocols.
-It is application components.
-It communicates using open protocols.
-It is self-contained and self-describing.
-It can be discovered using UDDI.
-It can be used by other applications.
-HTTP and XML is the basis for Web services.
Uses of Web Services
1. Connect existing software
a) Web services can help to solve the interoperability problem by giving different applications a way to link their data.
b) With Web services you can exchange data between different applications and different platforms.
2. Reusable application-components
a) There are things applications need very often. So why make these over and over again?
b) Web services can offer application-components like: currency conversion, weather reports, or even language translation as services.
WSDL stands for Web Services Description Language; WSDL is an XML-based language for describing Web services.
Any application can have a Web Service component. Web Services can be created regardless of programming language.