Most probably you have heard many, many times the three words, virtual file system, but what exactly do they mean? In my recent article What does this /proc directory do? I mentioned that it uses a virtual file system. The /sys directory also uses a virtual file system.
Modern secure distributions also like to use a virtual file system for their /tmp directories and to add more to the mix the device directory /dev has also moved to a virtual file system. These file systems are called, in order of my mentioning them, procfs, sysfs, tempfs and devfs. Uh, real imaginative naming scheme but logical. Virtual file systems are also used in presenting a common interface so different file system architectures can easily talk to each other. That last sentence is the key to the whole shebang.
All that a virtual file system does is translate from one language to another.
More Here .