On Linux dedicated servers, the hard drive is divided into partitions. There can be as few as two or several partitions, depending on the preferences of the system administrator. It is very important to understand the function of each partition on your new server and how they differ from Windows and other operating systems. What follows is a list of the default partitions followed by some other common ones.
/ – The default root partition is where all of the system files are stored. You will usually find /etc, /lib, and other important system directories under this partition. When installing a Linux distribution, the root partition is required.
/swap – Virtual memory is stored in the swap partition. Similar to Windows, the swap partition allows the system to simulate memory when the RAM is full. Unlike Windows, which uses a single file, Linux uses a separate partition that can hold numerous files. Usually, the swap partition will be as large as the amount of RAM. On systems with large amounts of RAM, swap may rarely be used.
Those are the two default partitions. Other partitions are optional but have security and stability benefits.
/usr – Executable binaries, kernel source, and documentation are stored here.
/var – You will find mail spool directories, logs, and often web server virtual hosts.
/tmp – Temporary files. Having a separate partition can be used as a security measure.
/boot – The kernel image and boot loader (usually Grub) are kept here.
/home – The users files for all real users are kept in /home. Keeping the directory on a separate partition can increase security as well.