The old scale lists an F5 tornado as wind speeds of 261â318 mph (420â512 km/h), while the new scale lists an EF5 as a tornado with winds above 200 mph (322 km/h), found to be sufficient to cause the damage previously ascribed to the F5 range of wind speeds.
Literature is a term used to describe written and sometimes spoken material. Derived from the Latin word, litteratura, meaning writing formed with letters, literature most commonly refers to works of the creative imagination, including poetry, drama, fiction, nonfiction, journalism, and in some instances, song.
I assume that by literature you mean something of high literary quality. In that case, Twilight isn't considered literature because it isn't very good. The writing is just not that high a quality and it contributes nothing new or valuable to the literary landscape.