1) The Hobbit - an adaptation of the book as we know it
2) LOTR prequel - a film documenting the events between The Hobbit and the start of Fellowship
Ah, thank you. Most interesting. Those events are a bit sketchy but I suppose they'd include the White Council's attack on Dol Guldur and Sauron's flight to Mordor. Perhaps the seduction and fall of Saruman. Maybe the re-awakening of the Nazgul. Beyond that I'm going on memory and it's coming up a little dry...
Right, The Hobbit is NOT a prequel to LotR. It's a stand on it's own book, it just happened to have happened before the time of LotR.