The Memory performance object consists of counters that describe the behavior of physical and virtual memory on the computer. ...

The Memory performance object  consists of counters that describe the behavior of physical and virtual memory on the computer.  Physical memory is the amount of random access memory on the computer.  Virtual memory consists of the space in physical memory and on disk.  Many of the memory counters monitor paging, which is the movement of pages of code and data between disk and physical memory.  Excessive paging, a symptom of a memory shortage, can cause delays which interfere with all system processes.