How is science fiction and fantasy alike?

There are many science fiction stories- the whole Atlantis genre, for example that have nothing to do with Space Travel but do go to Inner space- underwater, time travel, etc. Prepare to submerge!...

No, in fact many science fiction novel have been over-taken by recent event showing that their predictions are (were) actually true.

Science fiction, but it depends on how you look at it. I would say Sci-fi though, because it has beings from other planets in it. But it's up to you. Oh and S. Meyer says on her site that it's that.

To be honest, it varies a LOT, but I'll try my best to be helpful. Science fiction is generally of two key categories: dystopian or optimistic. But in general, the latter is more true. For example,...

they are both usually telling about different world(s) although science fiction is more futuristic and sciency that deals with space and time whereas fantasy has a more magical touch to it.