What makes ফ্যান্টাসি different from Sci-Fi?

I doubt wizards, witches, ghosts, goblins, dragons, and demigods have anything to do with science.

Boom.

Sci-fi is আরো about the future with future technology.

ফ্যান্টাসি is আরো about ancient creatures and legends and doesn't have to be in the future. Also ফ্যান্টাসি has nothing to do with humans and their advanced technology.

Sci-Fi,as আপনি might know,has to do with science,something that was caused/created দ্বারা science.
'Harry Potter' is fantasy,their's no science behind it অথবা in it,except Potions class,which is known as Chemistry.
'The Hobbit' is ফ্যান্টাসি as well,no science behind it অথবা in it.
ফ্যান্টাসি is usually made up.I mean,a completely different world,fairies,wizards,witches,mermaids,goblins,dwarfs,and hobbits aren't real,most commonly found in ফ্যান্টাসি stories.
'The Walking Dead' is a sci-fi based TV/comic book series.Zombies are created from science. A lab gone wrong,deadly disease,causing tons to die the return from the dead as flesh-eating,disease carrying zombies.Sci-fi can also be something that seems futuristic,like cylons,robot's,flying cars.
'Halo Reach' is the perfect example of a Sci-fi video games.Ther perfect combo of aliens,zombies,drama,Spartans,and science,all crammed into one amazing,adreniline pumping,addictive first-person-shooter.

well my best guess would be is ফ্যান্টাসি will be all of mythical creatures and magic used where scifi would be use of machines and aliens of course when some of these have magic and machines its hard to know what it is

boh i don't know

Simply what makes magic different from science. One is rational, explainable, and possible to the skeptic mind of this world; the other is irrational, unexplainable, and impossible for the skeptic mind to fathom.

Sci-Fi means something fictional can be backed দ্বারা science. It can also mean a scientific prediction of the future in বই like The Hunger Games. Fantasy, however, is all fiction and can't be backed দ্বারা science.

*pulls out তারকা Wars book and looks through it for any mention of fairies, dragons, অথবা magic* Nope. *pulls out Inheritance and looks through it for any mention of R2D2 অথবা Data* Nope.