Page table
A page table maps addresses in the virtual address space of a process which is indexed by the virtual page number and an offset within that page. The virtual page number is mapped to a physical frame number which combined with the offset can identify a location in physical memory. The simplest way to do this is with flat page tables. This is a page table contains one entry for each virtual page number which is the index in the page table. The page table entry then consists of the physical frame number a long with some management bits which inform the operating system if the memory mapping is valid, what permissions the process has for this memory. To then do the mapping it sums the offset from the virtual address with the physical frame number in the page table to get the physical address. Other page table types exist such as Multi-level page tables or Inverted page tables (IPT).