What's the difference between the 3 "Apple Keynotes" podcasts? I want to download a keynote for offline viewing, but I'm not sure how to decide between the three different podcasts:


Apple Keynotes
Apple Keynotes (HD)
Apple Keynotes (1080p)


I'm assuming that HD and 1080p are higher quality, and therefore take more space. Which one is higher quality?
In order of increasing quality &amp; size: Regular, HD, 1080p.

iMore forums:


  Normally when a video is referred to as HD. They are talking about
  720p. Which is a slightly lower quality compared to 1080p and if they
  say FHD (Full HD) they are talking about 1080p. I cant give you the
  exact space you need to store the videos since they can vary in
  length. But it could be over 1GB depending on the length.