XML Schema Complete Reference, The

21.6. Describing Applications

In many cases, the applications we create as developers exist in a box, unaware that any other applications exist. The only communication that such applications are aware of might be the initially defined communication between client and server. This communication occurs over a set protocol and possibly with a fixed set of data and time requirements. If an application never needs to communicate with the world outside its box, it does not necessarily need to publish its operations.

Increasingly, the applications we develop do not exist in a box. When successful, these applications rapidly become units of functionality that other processes or systems might wish to access. This is the concept of Web Services, creating ...