​Is the fire of Hell literal? Why?

No

There are 4 words translated "Hell" in the Bible.

Sheol and Hades are the most translated and they simply mean the grave and are sometimes translated grave or pit.

Then there is "Tartarus" --used only once and it is a verb meaning to be cast down--this is used to describe the condition of the fallen angels--cast down in chains of darkness--

Then there is Gehenna--this is literally a garbage dump--the valley of Hinnom. This is the place where the Israelites burned their children to the false god Molech. They burned their children alive and played loud music to drown out the screams. This practice was so despicable that the area was made into a garbage dump and nothing alive was thrown into it, but the perpetual fires destroyed everything that were thrown into it.

So, now read the parables and the scriptures in Revelation that use the word Gehenna with that understanding.

Then also note that parables are stories, so if the "hell fire" in the parable is literal then so is everything else--that is not how parables work--they are not meant to be taken literally. If you take them literally you miss the whole point of the parable.

Revelation is a book of symbols---so that being said--word pictures are used to get a point across, much like a parable.

Revelation also says death and hell are thrown into the lake of fire--so what does that mean?

It gives us the definition of what Gehenna actually is used to portray--the second death--that is eternal extinction. ​