Why is the linux file system refered to as hierarchical?

Answer 1

Because the person who named it was illiterate. Suffix "-al" turns a noun into an adjective (accidental; seasonal). Since "hierarchic" is already an adjective, the "-al" suffix is ungrammatical.

Answer 2

From the context of filesystems in general: If it supports directories and subdirectories, the filesystem is hierarchical. This is in contrast, to, say, the typical filesystem you found on CP/M computers in the early 80's such as a Kaypro 10, which organized files in "user" sections and had no concept of a "directory."

The term "hierarchical" in context of Linux could be a reference to how Linux, like any Unix or Unix-like system, is entirely UNIFIED in filesystems, meaning that when you stick in a thumb drive or a DVD-ROM or have another partition, they are "mounted" as opposed to the Windows method of assigning it a drive letter and treating it as a discrete filesystem with no link or relation to the other filesystems.

In Linux (And Unix(-lik)es in general.), a filesystem will be placed onto the same tree as all the others. For example, I have one filesystem for my Linux installation, and another filesystem for my data, documents, music, etc. While they are different "devices" to Linux, they are on the same tree (/ for the system partition, and my data is mounted on "/home." This method is actually superior and far more useful than the drive letter access system Windows uses. To your application software, it all looks like directories on a tree, but you can allow data to be distributed automatically between devices purely based on where the data was meant to go. Software can be installed in one partition while its configuration is on another while user data will be on yet another, yet, as long as the filesystems are mounted where intended, the application will behave as if all these things are available on the same tree.

Answer 3

The Linux file system is referred to as hierarchical, because it arranges files in directories, which are themselves arranged in directories, thus forming a tree.