A computer system is sometimes subdivided into two functional entities: hardware and software.
The hardware of the computer consists of all the  electronic components and electromechanical devices
that comprise the physical entity of the device.
Computer  software  consists  of  the  instructions  and  data  that  the  computer  manipulates  to  perform
various  data-processing  tasks.  Program  A  sequence  of  instructions  for  the  computer  is  called  a
program. The data that are manipulated by the program constitute the data base.
Computer organization  is concerned with the way the hardware components operate and the way they
are  connected  together  to  form  the  computer  system.  The  various  components  are  assumed  to  be  in
place  and  the  task  is  to  investigate  the  organizat ional  structure  to  verify  that  the  computer  parts
operate as intended.
Computer  design  is  concerned  with  the  hardware  design  of  the  computer.   Once  the  computer
specifications  are  formulated,  it  is  the  task  of  the  designer  to  develop  hardware  for  the  system.
Computer design  is concerned with the determination of what hardware should  be used and  how the
parts  should  be  connected.  This  aspect  of  computer  hardware  is  sometimes  referred  to  as  computer