Extending the set of built-in DSC resources is possible by importing additional resources as part of PowerShell Modules as well.
A compilation job in Azure Automation DSC refers to the process of creating a node configuration by compiling a configuration file. Following a compilation job, a node configuration is automatically placed on the Azure Automation DSC pull server. Previous versions of the configuration are overwritten.
There are, of course, other terms you may encounter. However, these are the most important. As long as you are familiar with these terms, you should be able to carry an intelligent conversation about the workflows involved in Azure Automation DSC.