3D films are movies that create the illusion of depth, making the viewing experience more immersive. They achieve this effect by using two slightly different images, one for each eye, which the brain combines to perceive three dimensions. Special glasses are typically worn to view these films, allowing audiences to feel as if they are part of the action. The technology behind 3D films has evolved over the years, with various methods like anaglyph, polarized, and active shutter systems. Popular in genres like animation and action, these films aim to enhance storytelling by adding a visual layer that engages viewers more deeply.