Mistakes are the portals of discovery.
In this chapter we’ll describe two kinds of Web systems: application infrastructures and service infrastructures. Many of us build applications that have Web front-ends. These front-ends access business layers and persist their data in databases. Application infrastructures provide the basic layered architecture for these types of systems. In contrast, service infrastructures collaborate with each other using the Web, in addition to interacting with users. They have Service-Oriented Architectures (SOA).
There are issues common to both types of systems; we would like to have a foundation for creating large, well-structured Web systems that are ...