No. You have destroyed a particular physical book,
but not the information that is the novel Tom Sawyer.
(You will still have to write that book report.)
Information is funny stuff.
The information for the web page you are looking at
is recorded on a hard disk
inside a computer located in New Britain, Connecticut.
The information was copied from that physical device to other physical devices
perhaps hundreds of times
before it got to your computer where your web browser
is using it to display these words on your monitor.
Clearly information is something different from
the devices used to store and transmit it.
A computer system consists of both hardware
and information stored on hardware.
Information stored on computer hardware is often called software.
The hardware components of a computer system are the
electronic and mechanical parts.
The software components of a computer system are the
data and the computer programs.
to see the desktop system these notes were originally prepared on.
(This was back when anything to do with computers had to be beige.
Everything in this picture has since been replaced, except for
The major hardware components of a computer system are:
- Main memory
- Secondary memory
- Input devices
- Output devices
For typical desktop computers,
the processor, main memory, secondary memory, power supply, and supporting hardware are
housed in a metal case.
Many of the components are connected to the main circuit board of the computer,
called the motherboard.
The power supply supplies power
for most of the components.
Various input devices (such as the keyboard)
and output devices (such as the monitor) are attached
through connectors at the rear of the case.
Is a mouse an input device or an output device?