In this chapter, we have reviewed Puppet modules, exploring various aspects of their function. We saw how Puppet language evolution has influenced the design of modules, in particular regarding how parameters are exposed and managed, from class parameterization to data in modules. We have also seen common approaches like the params and the anchor patterns. We have analyzed the different kinds of parameters a module can expose and where they can be placed. We have also covered the stdmod naming convention initiative. We have studied some of the reusability options we can add to modules to manage configuration files, extra resources, custom classes, and installation options.
Now it's time to take a further step and review how we can organize modules at a higher abstraction layer and how people are trying to manage full stacks of applications. This is a relatively unexplored field, where different approaches are still trying to find common consensus and adoption.