[W/K] :: main memory

  main memory \main memory\ n. (Computers)
     The memory in a computer that holds programs and data for
     rapid access during execution of a program; it usually hold
     the largest quantity of rapid-access storage in a computer;
     -- also called RAM ({random access memory. It is
     contrasted to ROM, disk data storage, cache,
     registers and other forms of data storage.
     [PJC]

  main memory
       
           The storage device used by a computer
          to hold the currently executing program and its working data.
          A modern computer's main memory is built from random access
          memory integrated circuits.  In the old days ferrite core
          memory was one popular form of main memory, leading to the
          use of the term "{core" for main memory.
       
          Computers have several other sorts of memory, distinguished by
          their access time, storage capicity, cost, and the typical
          lifetime or rate of change of the data they hold.  Registers
          in the CPU are fast, few, expensive and typically change
          every few machine instructions.  Other kinds are cache,
          PROM, magnetic disk (which may be used for virtual
          memory), and magnetic tape.
       
          (1996-11-04)