Comparison of

• input devices
  • Digital Camera
    • Resolution – Measured in mega pixels, typically the larger the better.
    • Optical Zoom – How close you can make the image appear without losing any quality.
  • Touch Screen
    • Resistive – Single touch
    • Capacitive – Multi touch
• output devices
  • Printers
    • Resolution – Measured in DPI (dots per inch)
    • Speed – Measured in PPM (pages per minute)
    • Type – Laser or Ink Jet
  • Monitors
    • Size – Measured diagonally in inches (9″,21″)
    • Resolution – Measured in pixels (1920×1080)
    • Type – LCD/TFT uses a flat panel of coloured cells to change the colour of the light shining through it. OLED uses a  matrix of tiny LEDs to produce an image.
• processor type – How many bits can be processed in a single operation (16bit, 32bit, 64bit )
• number of processors – Single Core, the processor can appear to do more than one thing at a time using time slicing.  Multi core, different processes are run on different cores.
• Processor speed (Hz) – The number of times per second the processors voltage is switched, this allows the processor to carry out an operation. Typically measured in Gigahertz (GHz).
• memory
  • RAM – Volatile, losses contents when power disconnected. Dynamic, requires constant refreshing to remember contents.
  • ROM – Non Volatile, contents kept when power disconnected. Not writeable, contents can not be changed.
  • cache – Located on (or very near) processor. Static, contents do not need refreshing.
• device type
  • Desktop – Used for tasks that require a fair amount of processing power and storage.
  • Laptop – Portable devices that use a battery and keyboard.
  • Tablet – Ultra Portable device that uses a battery and touch screen.
  • Smartphone – Small Ultra Portable device that uses a batter and small touch screen.