You are assisting a user in trying to find a file in their C:\Users folder. You see that some of the folders appear differently than the others, appearing to be faded in, rather than full color. What do these icons refer to?
Folders that are grey and "ghosted" are hidden folders. These typically hold back-end information or files that the user does not need to access.
Wikipedia
In computing, a hidden folder (sometimes hidden directory) or hidden file is a folder or file which filesystem utilities do not display by default when showing a directory listing They are commonly used for storing user preferences or preserving the state of a utility, and are frequently created implicitly by using various utilities They are not a security mechanism because access is not restricted - usually the intent is simply to not "clutter" the display of the contents of a directory listing with files the user did not directly create