A projector is a machine that takes an image from a computer, phone, or video player and displays it much larger on a wall or screen. You've probably seen one in your classroom when your teacher shows a video or presents a slideshow: the projector beams light through tiny colored pixels to create a big, bright picture that everyone can see at once.

Modern projectors use powerful bulbs and special lenses to make images sharp and clear, even when projected across a large room. Movie theaters use giant projectors to show films on massive screens. Before digital projectors, old-fashioned film projectors would shine light through strips of film, displaying one frame at a time so quickly that it looked like smooth motion.

A projector projects light and images outward onto a surface. You might also hear about an overhead projector, which teachers used to place on their desks to display transparent sheets, though these have mostly been replaced by digital projectors. Some people even have small projectors at home to watch movies on their living room wall, turning an ordinary room into a mini theater.