Animations
Some ideas are about movement: a value flowing through a pipeline, a tree rebalancing, a cause rippling into its effect, change over time. For those, an explainer includes short animated scenes, drawn with shapes, arrows, labels, and graphs that build and move in front of you.
The animation is synced to the narration: the scene's steps play in the order the voice explains them, stretched to match the length of what's being said. It plays in place on the slide, like a short embedded video, except it was written for your specific question. Where an animation shows change over time, a diagram shows fixed structure and a code slide shows the source itself.
Getting good animation slides
Most explainers include an animation on their own. If you know what you want to see move, say so: animate how the packet travels or show the array being sorted step by step.