Roughly speaking, Linux is a versatile operating system that supports a wide range of file systems. This is made possible by the unified interface of the Linux kernel. This unified interface is known as "virtual file interface." Note that it's not a file system on its own but an interface that provides a clearly defined link between the operating system kernel and different file systems..
Read more over at OS Weekly.
Linux File System Demystified
Posted on Thursday, April 20 2006 @ 6:14 CEST by Thomas De Maesschalck