[1] When a speaker is verbally addressing an audience, it is often necessary to use supplementary equipment and media to clarify the point.
At a basic level, visual content can be provided by drawing directly onto a blackboard or whiteboard during the presentation.
Laser pointers or sticks are often used to highlight a particular point of interest within a slide or image.
Many manufacturers produce devices that provide remote control over electrical presentation equipment, thus allowing the speaker to move around the stage freely and to activate systems when they are required.
For example, the presenter may attempt to describe a complex mechanical movement, in which case animation or video may provide the clearest method of delivery.