Comprehensive software for organizing files, viewing files, browsing through directories, moving files, renaming files, deleting or recovery of files, often searching, compressing/decompressing, or other features. The sort of thing the Windows Explorer or File Manager, or Macintosh Finder program does.
DOS file managers are mostly text-view, though some do use a mouse if one is installed. As the operating system is no longer maintained by its original manufacturer, many of the early and famous DOS file managers, Norton Commander, XTree, and DOSShell are also only supported by a fan base, but it is a large and enthusiastic fan base.
The built in Macintosh file manager program is called the Finder. These programs augment or replace it.
Unix and Linux file managers, programs to organize, delete, rename, move files.
Windows file managers, programs to organize, delete, rename, move files.