10.2. What web services are not

Web services are not the solution for every software system communication.
Nowadays they are meant to be used for loosely-coupled coarse-grained communication, message (document) exchange. Recent times has seen many specifications (WS-*) discussed and finally approved to establish standardized ws-related advanced aspects, including reliable messaging, message-level security and cross-service transactions. Web service specifications also include the notion of registries to collect service contract references, to easily discover service implementations.
This all means that the web services technology platform suits complex enterprise communication and is not simply the latest way of doing remote procedure calls.