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 and in more recent times, overhead projectors are being used/designed to project things on technological devices. This machine has a plastic frame that would be placed on top of the projector, and a fan that cools the machine from overheating if used for long periods of time.