Active shutter technology is a method used in 3D displays to create the illusion of depth. It works by rapidly alternating between two images, one for each eye, while special glasses with liquid crystal lenses open and close in sync with the display. This allows each eye to see a different image, enhancing the 3D effect. The glasses contain batteries and are often synchronized with the display using infrared signals. This technology is commonly found in 3D televisions and cinemas, providing an immersive viewing experience. However, it requires the use of specific glasses, which can be a drawback for some users.