What is the difference between a Film-script and a simple story for film-making?

I have ideas of stories on which I want a producer to make films. But I can simply write a novel or a story keeping in mind visual facts so that a film can be made on them. But I don't know how to write a script. What is the difference between a script and a story?|||Sorry my friend.....it is hard to understand by giving words.......but i can give you something to understand what is script........plz download final draft software at torrent and get tutorials from youtube........i hope i help you.....