What is the difference between a Widget and a Phone App???

WHat does a WIdget can do that a Phone App can't and opposite??

And if I create a widget or a phone App with Adobe Edge..How can I make it available on the net for people to download and install it on their phone (sorry my question is maybe silly lol)

FOr instance : can I put it on my website with a link to download it? or does it need to be in a store of Apps or Widgets?

Thanks!