Each backslash is a folder. This document is down in a third-level of the folder list. Sometimes that's called a tree, because if you drew a chart of where all the files are, it would have a lot of branches. The best backup of business data is one that isn't in your office during the fire. Or the break-in.
Every computer has a portable file cabinet, called a floppy drive.
It holds diskettes, which aren't floppy, but that's just a name that dates back to the type of diskettes used in the 1980's. A diskette doesn't hold much, maybe a few dozen small documents or one large one. It's more useful for sending copies of files somewhere else than for making backups. A bigger portable file cabinet is a Superdisk or a ZIP disk or magneto-optical disk. They all hold around 100 to 200 times as much stuff as a diskette.