The industry is in a bit of a transition period regarding that. Digital cinema has been developed, standardized, and distributed. North America tending to lead the race on anything cinema-related, generally, is ahead of the rest of the world I would guess, but still, only about 30% of cinemas use digital projection for feature films in the United States so far.
The rest of us (my cinema included, we haven't made the "digital swap" yet) still does use those "old" cans of film. 35mm film to be specific. They aren't really shipped in cans anymore, not for Hollywood films, but the cinema where I work also regularly shows foreign films (mostly from India) which come shipped in cans. Hollywood films come nicely packed on plastic reels that's compatible with our equipment for building up (assembling it from the small reels - which are on average about 20 minutes of footage each) movies. The Indian ones are incompatible with our equipment but can be "brute forced" on so to speak. It's a real pain in the ass.
Especially considering we normally receive them on a Friday, build it up, play it once or maybe twice, then we have to tear it back down and put it into its cans the next day.