Page (computer Memory)

Page (computer Memory)

A page, memory page, or virtual page is a fixed-length contiguous block of virtual memory, and it is the smallest unit of data for the following:

  • memory allocation performed by the operating system for a program; and
  • transfer between main memory and any other auxiliary store, such as a hard disk drive.

Virtual memory allows a page that does not currently reside in main memory to be addressed and used. If a program tries to access a location in such a page, an exception called a page fault is generated. The hardware or operating system is notified and loads the required page from the auxiliary store automatically. A program addressing the memory has no knowledge of a page fault or a process following it. Thus a program can address more (virtual) RAM than physically exists in the computer. Virtual memory is a scheme that gives users the illusion of working with a large block of contiguous memory space (perhaps even larger than real memory), when in actuality most of their work is on auxiliary storage (disk). Fixed-size blocks (pages) or variable-size blocks of the job are read into main memory as needed.

A transfer of pages between main memory and an auxiliary store, such as a hard disk drive, is referred to as paging or swapping.

Read more about Page (computer Memory):  Page Size Trade-off, Determining The Page Size in A Program, Huge Pages, See Also

Famous quotes containing the word page:

    There is then creative reading as well as creative writing. When the mind is braced by labor and invention, the page of whatever book we read becomes luminous with manifold allusion. Every sentence is doubly significant, and the sense of our author is as broad as the world.
    Ralph Waldo Emerson (1803–1882)