The document discusses various types of projected and non-projected audiovisual aids used in teaching. Projected aids include film/slide projectors, overhead projectors, LCD projectors, and interactive whiteboards. They allow images and writing to be projected large-scale for all students to see. Non-projected aids include charts, diagrams, models, and pictures that do not require projection equipment. Both types can enhance learning by appealing to multiple senses and making lessons more engaging. The document provides examples and advantages of different aids to support effective teaching.