CH 3 SC 11 Setting Your Virtual Machine Swappiness for Optimal Performance.

Swap space in Linux is a form of virtual memory that is used for additional memory resources when the physical memory (RAM) is full. Swap space consists of space on a hard disk that is set aside for use by the operating system. When the system runs out of RAM, the inactive pages of memory (pages that have not recently been used) will be moved from the RAM to the swap space, freeing up RAM for other uses. This process is known as swapping. Swap space allows the system to continue running even if the RAM is full, preventing the system from crashing. Swap space can also be used as a form of backup memory when the system is running low on RAM; this helps to prevent any data loss.