The idea of other modules is optional modules that provide additional functionalities or utilities: for example, modules that need to generate Axis2 services and service proxies. Axis2 does not use these modules at the runtime, and as mentioned earlier, those are only to provide additional features. Axis2 uses them as tooling modules to generate service-side code and client-side code.
Code generation: Axis2 provides a code generation tool that generates server-side (skeleton) and client-side code (stub or proxy) along with descriptors and a test case. The generated code would simplify the service deployment and the service invocation. This would increase the usability of Axis2.
Pluggable data binding: The basic client API of Axis2 lets the user process SOAP at the XML InfoSet level, whereas data binding extends it to make it more convenient for the users by encapsulating the InfoSet layer and providing a programming language-specific interface.