A software system designed to support interoperable machine-to-machine interaction over a network. Web service refers to a client and server that communicate using Extensible Markup Language (XML) messages adhering to the Simple Object Access Protocol (SOAP) standard. A web service is invoked remotely using SOAP or Hypertext Transfer Protocol (HTTP)‑GET and HTTP‑POST protocols. The web service returns a response to the client in XML format. Any operating system that supports the SOAP protocol and XML can build and consume a web service.