File System in Linux

A  filesystem, which is the embodiment of a method of storing and organizing arbitrary collections of data in a human-usable form.

Different Types of Filesystems Supported by Linux:

• Conventional disk filesystems: ext2, ext3, ext4, XFS, Btrfs, JFS,NTFS, etc.
• Flash storage filesystems: ubifs, JFFS2, YAFFS, etc.
• Database filesystems
• Special purpose filesystems: procfs, sysfs, tmpfs, debugfs, etc.
• Partitions and Filesystems
  A partition is a logical part of the disk, whereas a filesystem is a method of storing/finding files on a hard disk (usually in a partition). By way of analogy, you can think of filesystems as being like family trees that show descendants and their relationships, while the partitions are like different families (each of which has its own tree).
  A comparison between filesystems in Windows and Linux is given in the following table:

  	Windows	Linux
  Partition	Disk1	/dev/sda1
  Filesystem type	NTFS/FAT32	EXT3/EXT4/XFS...
  Mounting Parameters	DriveLetter	MountPoint
  Base Folder where OS is stored	C drive	/

The Filesystem Hierarchy Standard

Linux systems store their important files according to a standard layout called the Filesystem Hierarchy Standard, or FHS. You can download a document that provides much greater detail here, or look up the original source documents on the Linux Foundation website. This standard ensures that users can move between distributions without having to re-learn how the system is organized.

Linux uses the ‘/’ character to separate paths (unlike Windows, which uses ‘\’), and does not have drive letters. New drives are mounted as directories in the single filesystem, often under /media (so, for example, a CD-ROM disc labeled FEDORA might end up being found at/media/FEDORA, and a file README.txt on that disc would be at/media/FEDORA/README.txt).

All Linux filesystem names are case-sensitive, so /boot, /Boot, and /BOOT represent three different directories (or folders). Many distributions distinguish between core utilities needed for proper system operation and other programs, and place the latter in directories under /usr (think "user"). To get a sense for how the other programs are organized, find the /usrdirectory in the diagram above and compare the subdirectories with those that exist directly under the system root directory (/).