ASIDE: DATA STRUCTURE — THE PAGE TABLE
One of the most important data structures in the memory management subsystem of a modern OS is the page table. In general, a page table stores virtual-to-physical address translations, thus letting the system
know where each page of an address space actually resides in physical memory. Because each address space requires such translations, in general there is one page table per process in the system. The exact structure of the page table is either determined by the hardware (older systems) or can be more flexibly managed by the OS (modern systems).