Ive seen different versions of the same movie on blu-ray such as "The dark Knight" , one disc and two disc. Also i have seen different screen variations. What im looking to find out is are the only one version of each movie but with added content or are there actually differences in the movies contained on the different discs. In the past i could get a dvd with widescreen on one side and then full screen on the other. Ive got a few BR's now but im wondering if im getting the movies in a format other than what i want. so basically are there more than one format for movie releases.