DaveWentzel.com All Things Data
Namespaces as Drives
All namespaces are exposed in PS as drives, meaning you can manipulate a namespace just like you do a standard disk drive. This includes the registry, Functions, variables, aliases, and environment variables.
The following lists all "drives" available:
get-psprovider is a slightly different way of seeing the same data. I think this output is a little more useful because it shows you exactly what drives are available.