A projector is an optical device that projects an image or video onto a surface, usually a screen or wall, for display or presentation purposes. It works by receiving a video signal from a source, such as a computer, Blu-ray player, or gaming console, and then using a light source, lenses, and mirrors to enlarge and project the image.

Key features to consider when choosing a projector include:

1. Brightness (measured in lumens)
2. Resolution (e.g., HD, Full HD, 4K)
3. Contrast ratio
4. Connectivity options (e.g., HDMI, USB, wireless)
5. Portability and weight

Projectors are widely used in various settings, including -
Home theaters: For movie nights and gaming.
Classrooms: For educational presentations and lectures.
Conference rooms: For business meetings and presentations.
Cinemas: For movie screenings.