Overhead projector
An overhead projector (OHP) is a device that allows you to display images from either a computer/laptop or images created in real time. Overhead projectors were often used in classrooms to showcase some type of presentation on paper for a group of students to view. In more recent times, overhead projectors are being used and designed to project things on technological devices. This machine has a plastic frame that is placed on top of the projector, and a fan that cools the machine, so that it won't overheat if it is used for long periods of time.