This document provides information about different types of projected audio-visual aids including overhead projectors, slides, filmstrips, and movies. It defines each type of projected aid and describes how to create and use them, listing advantages and disadvantages. Overhead projectors project enlarged images of transparencies onto a screen. Slides are small transparent pieces with single images photographed onto them. Filmstrips are sequences of frames that are manually advanced. Movies originally just contained filmstrips but later developed audio and improved technology. All of the projected aids can enhance teaching by engaging students visually but require dark rooms and some may be outdated.