If you want to move to the next level then there is not much more to
learn, most presentations work pretty much similar to each other, just one
has more/less of something than other.  And we (user) don't need to know
what or how they do but just enable whatever they have to ofter, then enjoy
whatever the slection may be.  Or in general

- They all do slideshow or presentation, save to hard drive or burn to
CD/DVD.  Plenty of options to please most if not all

- Some offer more/less transitions than other, and some may have different
effect's.  I chose ProShow Gold because it offers more of this

- Caption, some offers caption option when other may not.  And more/less
features/options

- Audio, I believe most if not all lets user to add audio to the
presentation, and to control the audio etc..

    That's about what most presentation programs do, and some offers more
unique features/options to make them stand out from the rest.  While the
basic slideshow from most graphic viewers just display one photo after
other, some may have few basic transitions (ProShow Gold has around 300
screen effects).