note: some of the information is posted in comments,
if you'll fork this gist, you'll loose that information,
it is best to just bookmark this one..
WIM (ESD,SWM) is an image of an OS file system,
it can be mounted, and modified (to some degree) .
there are two possible ways, through DISM or through mounting it directly through an older way, using a driver named imagex
(Windows Imaging Utility).
regardless,
terminology