What is "directory"

Directory, board or briefcase is a structure used to organize files on a computer or a file that contains references to other files.

A directory may contain references to files and other directories, which may also contain other references to files and directories. This can extend a lot. You can have, for example, twenty directories, one inside the other.

The directories therefore serve to organize the hard disk and other media (floppy disks, Zip Disks, Cds, Dvds, memory cards, USB flash drives, etc.). Thanks to them, we can put the most important files in a corner so that they are not changed, group files by owner, type, or the way you want.

This whole structure of files and directories can be seen as a tree. Thus, the main directory, which has no name, is known as the root ("root", in the original English), the directories are branches and the files are the leaves.

Source: Wiki