On NeXTSTEP and OS X, the /Apps (/Applications) directory is for self-contained application bundles that hold a GUI application and all of its dependencies that aren't part of the base OS, and they can be installed and removed by dragging and dropping that one bundle (which is a directory, but appears in the graphical file manager as a single object). There was also a distinction between locally-installed stuff and network resources which made things a little more complex but more manageable if you were actually working in an office full of NeXT boxes. OS X still has /usr and it still has pretty much the same meaning, but GUI apps live in a separate and more user-friendly domain.
Known on Windows world as xcopy install, due to the similar way MS-DOS software used to be bundled and everyone used xcopy instead of the pretty basic copy that didn't do recursive copies.
But sadly it doesn't present the nice object concept NeXTSTEP and OS X have.
