Abstract: A web service is a software system designed to support interoperable machine-to-machine interaction over a network. Web service is a service offered by one electronic device to another electronic device by communicating with each other over World Wide Web. Web services can be classify in two classes REST-compliant web services and arbitrary web services. SOAP (Simple Object Access Protocol) is intermediate language so that the applications written in different language can talk with each other. That means SOAP is language independent. SOAP is also platform independent. SOAP is based on XML and XML is light-weight so SOAP is also light-weight. REST stands for Representational State Transfer. It relies on a stateless, client-server, cacheable communications protocol and in virtually all cases, the HTTP protocol is used. REST is an architecture style for designing networked applications. The idea is that, rather than using complex mechanisms such as CORBA, RPC or SOAP to connect between machines, simple HTTP is used to make calls between machines. If we used SOAP or CORBA then there is requirement for client side to use the same because there is tight coupling. In many ways, the World Wide Web itself, based on HTTP, can be viewed as a REST-based architecture. RESTful applications use HTTP requests to post data (create and/or update), read data (e.g., make queries), and delete data. Thus, REST uses HTTP for all four CRUD (Create/Read/Update/Delete) operations. In REST two software can be integrated. In REST each data element is a resource, addressed by a URI (Uniform Resource Identifier).
Keywords: web service, SOAP, WSDL, UDDI, RPC, REST.