Web service

A web service is a broad term referring to various client-server approaches to distributing software across a network. More narrowly, a web service is a program addressable by a URL on a web server, which can be invoked from a client machine elsewhere on the network. Conceptually, a web service may be regarded as an application programming interface (API) distributed across a network and callable by the client without regard for the underlying operating system on which the web service runs.