You begin with DSC by writing a configuration script in PowerShell. The script itself doesn't actually do anything. You can run the script interactively all you want; it won't change a thing. Since the configuration script is the DSL we were talking about earlier, it's only a list of things to do, not the things that actually execute the list. Because there can only be one MOF per target host and each configuration script is translated to an MOF, this means there is usually only one configuration script you write, which handles all the variances in your environment. This sounds like it will get complicated and difficult to manage quickly, but there are DSC patterns to follow in order to manage this. We will cover these in Chapter 3, DSC Configuration Files.

The next step is to translate the configuration script to an MOF file. The translation, or compiling, happens only once—when you deploy the MOF file to the target node or to the DSC pull server. The configuration script is often kept in a version control system and only compiles and deploys the MOF file when the configuration script changes.