Web services are a variety of tools which can be used in a lot of means, of which the most common usage style are RPC, SOA and REST.

RPC Web services shows a scattered method call interface which is most known to developers. The most basic part of this services is the WSDL Operation.

Because the initial web services tools centered on RPC, this style is now widely spread and highly supported.

The goal of RPC in general is make distributed programming as easy as possible by creating the illusion that an exchange of data over the network that results in some processing (on another machine than the one the application is running on) is nothing more than a special kind of procedure call — one that has the special attribute of being “remote”.