The master copies of all the shows and movies available to Netflix take up 3.14 petabytes of storage space. (In comparison, Facebook uses about 1.5 petabytes to store about 10 billion photos.) Hollywood studios used to send individual films and shows to Netflix on a disc or thumb drive; now they use a Netflix system called Backlot to send encrypted files via the Internet. Netflix then compresses the files and creates more than 100 different versions, each tuned for the varying bandwidth, device, and language needs of its customers. (An hour of video for the iPhone would be about 150 megabytes.) This compressed catalog comes to about 2.75 petabytes.