The document compares the obsolete overhead projector technology to the emerging interactive whiteboard technology. It notes that overhead projectors only allowed one-way information sharing from teacher to students, while interactive whiteboards enable two-way interaction between teachers and students. It also states that interactive whiteboards allow incorporation of richer multimedia content into lessons and provide increased flexibility for teachers to interact with students. The emerging technology of holograms is predicted to eventually replace interactive whiteboards by enabling even more immersive three-dimensional teaching experiences.