Frames, pages and slots

People often confused terminology in IT. Memory is one prime area for such confusion.

  • A block of real storage is a frame
  • A block of virtual storage is a page
  • A block of auxiliary storage is a slot

Virtual storage is the technique whereby a programmer need not know whether or not a piece of information is actually in memory at any point in time. The underlying operating system takes care of this, using paging to reduce the amount of (and cost of) real storage (i.e. RAM) while still presenting an infinite or near-infinite storage capacity to each application program.

Paging is the transfer of a block of storage between auxiliary storage slots and central storage frames. Inactive frame contents are paged out to auxiliary slots. As required, the contents of slots are paged in.

Learn more:

How z/OS uses physical and virtual storage