The notebook computer is used to display text and graphics during presentations. Basically, it can display anything that you put on your computer screen, including entire presentations generated by presentation software. An excellent tool if used in moderation, but not as an alternative to you—the speaker. It is often used in conjunction with an overhead projector or other projector, which projects the image from the computer screen onto the wall screen.
whiteboard The whiteboard (more rarely blackboard or greenboard) is a useful device for spontaneous writing - as in brainstorming, for example. For prepared material, the OHP might be more suitable.