A projector is an electronic device used to project images or videos onto a large screen or wall. It works by shining a light through a lens system to display an enlarged image. Projectors are commonly used for presentations, movie screenings, and gaming. There are several types of projectors including LED, LCD, DLP, and LCoS, each with their own unique features and benefits. They can be connected to various devices such as a computer, DVD player, or streaming device to display content.