Spring Integration offers a number of configuration options. Which option you choose depends upon your particular needs and at what level you prefer to work. As with the Spring framework in general, it is also possible to mix and match the various techniques according to the particular problem at hand. For example, you may choose the XSD-based namespace for the majority of configuration combined with a handful of objects that are configured with annotations. Of course, it is also possible to always stick with a single approach. The main point is that these are options for configuration motivated by the need to support a user community with a wide range of preferences. That said, there has also been a concerted effort to provide consistent naming so that, for example, the XML elements defined by the XSD schema will match the names of annotations, and the attributes of those XML elements will match the names of annotation properties. Direct usage of the API is yet another option and is described in detail in Chapter 2, The Core API. We expect that most users will choose one of the higher-level options, such as the namespace-based or annotation-driven configuration.