A projector that projects an image or moving images onto a surface, typically a projection screen, is known as an image projector or projector. The majority of projectors produce images by shining light through a small, transparent lens; however, some more recent models can project images directly by employing lasers. Instead of using an external projection screen, a projector known as a virtual retinal display or retinal projector projects an image directly onto the retina. A video projector is the most common type of projector used today. Digital video projectors take the place of older types of projectors like overhead and slide projectors.

3D projection is a design technique for displaying a three-dimensional (3D) object on a three-dimensional (3D) surface. These projections project a complex object onto a simpler plane using visual perspective and aspect analysis for viewing capability.