What is the purpose of using annotations during a slide show?

Using annotations during a slide show serves the purpose of highlighting key points during delivery. When presenting information, it's essential to engage the audience and draw attention to specific elements that are being discussed. Annotations, such as handwriting or drawing directly on the slides, allow presenters to emphasize these points in real-time, making the presentation more interactive and personalized. This approach helps maintain the audience's focus and can reinforce the main ideas being conveyed, ultimately enhancing the overall effectiveness of the presentation.

The other options relate to features that serve different functions. Permanently editing slide content involves making changes to the text or images on the slides before the presentation, which does not apply to on-the-fly highlighting during a show. Applying themes pertains to the overall design and visual appeal of the slides, rather than the act of emphasizing particular points during a presentation. Changing font styles also affects the design of the slides in a permanent way and does not facilitate real-time engagement or emphasis during delivery.