Understanding the memory management scheme known as Paging can be helpful when troubleshooting DXi performance issues. This article is meant to provide a basic and easy to understand description of how paging works. 

Virtual Memory

Virtual memory is a function/technique where processes are provided with large, isolated memory address spaces. The image below, copied from Wikipedia, shows the basic concept. A contiguous range of virtual memory addresses is allocated for use by a process and those addresses are mapped to physical memory or disk. This provides multiple benefits, some of which include no need for shared memory management and providing address spaces larger than existing physical memory. 

                                        

Paging

 Paging is one of the memory management methods used for mapping virtual memory to physical memory or disk.