What is the difference in troy the movie and troy the book?

The Iliad

"Troy" was loosely based upon the Greek classic written by Homer entitled " The Iliad " .

yes

As it is a war saga, look at some competing films of the past- the motion picture The Longest Day- was entirely about the Normandy Invasion- also called D-day, but did opt for an original title-...

u must be the one to figure it out