'Hard disc' and 'diskette' - what's the difference?

Roughly speaking 'suitcase' and 'purse/wallet':

  Hard disc - large storage capacity, relatively expensive to buy, cheaper per unit stored, normally fixed internal installation, reliable...
  Floppy diskette - minimal storage capacity, cheap to buy, more expensive per unit stored, readily movable, unreliable
  Other solutions are under development: portable Zip and Jaz discs, reusable CDs, network computers, etc.

'Hardware' and 'software'?   'Operating system' and 'program'