# Memory Vmstat
To monitor memory usage in the system, use a monitoring tool that provides reports about CPU activity in the system.
## **Memory Pages In / Out**
Displays the number of memory pages loaded from secondary storage to physical memory within a specified time period.
Memory Vmstat
## **Memory Pages Swap In / Out**
Displays data transfer activities between physical memory and swap space on the Linux operating system.
Memory Vmstat
## **Memory Page Faults**
It is a process in which the operating system tries to access memory pages that do not currently exist in physical memory and must be obtained from secondary storage, such as disk.
Memory Vmstat
## **OOM Killer**
A mechanism in Linux systems that is responsible for terminating processes when physical memory and swap space run out.
