Projectors work by using different technologies to project images or video onto a screen. The main types are CRT, LCD, DLP, and LCOS. CRT projectors use electron guns and phosphors to create images. LCD projectors use backlights and liquid crystal panels to control light transmission for each pixel. DLP projectors use an array of microscopic mirrors to rapidly reflect light and form images. LCOS projectors are similar to LCD but use reflective silicon backplanes instead of glass for better image quality. All projector types work by precisely controlling light to reproduce colors and create projected pictures.