film projection

Film projection is the process of displaying motion pictures by shining light through transparent film stock onto a screen.

A projector pulls the film past a bright lamp at a constant rate—traditionally 24 frames per second—creating the illusion of continuous movement through persistence of vision.

Before digital cinema became standard in the early 21st century, virtually all theatrical movies were shown this way, with reels of 35mm film threaded through mechanical projectors by trained operators.