The Unix filesystem, which is used by most Unix-based operating systems, including Linux, consists of a virtual filesystem tree, which is the frontend to the user and applications. The tree starts with the root (that is, /), and all files, devices, and other resources are located within this single root directory.
From there, a physical filesystem is usually mapped onto the virtual filesystem, providing a mechanism by which files are stored and retrieved. It should be noted that this physical filesystem does not have to be a disk; it could also be RAM or some other type of storage device.
To perform this mapping, the operating system has a mechanism for instructing the OS to perform this mapping. On Linux, this is done using /etc/fstab, as follows:
> cat /etc/fstab
UUID=... / ext4 ...
UUID=... /boot/efi vfat ...
As shown in this example, the root filesystem...