Web services is a software system designed to support interoperable machine-to-machine interaction over a network. It has an interface described in a machine-processable format (specifically WSDL). Other systems interact with the Web service in a manner prescribed by its description using SOAP messages, typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standards. Web services are classified into two types SOAP and RESTful. SOAP is Simple Object Access Protocol which has its own pre-defiened structure envelope and header REST is Representational State Transfer it does not have any pre defined structure