When a program is first loaded, the logical memory address range of the application is divided into fixed size units called pages. As each page is referenced by a program, it is mapped to a physical page that resides in physical memory. The mapping is dynamic which ensures that logical addresses that are frequently referenced reside in physical memory. Remember that each individual process that is launched is allocated its own virtual address space and application program threads are only permitted to directly access the virtual memory locations that are associated with their parent process’ address space. This is where Page Tables come into play.
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