An interactive visual is a small, self-contained thing students can actually play with inside a lesson, rather than a picture of the idea. A pendulum they can lengthen. A dice roller that builds up a distribution. An algorithm they can step through one line at a time. A scenario that branches on the choices they make.
Adding one
In a lesson page, add a block and choose Interactive visual. You can also type / and search for it.
The block then offers two routes:
Generate new. Describe what you want and it gets built for you.
Select existing. Pick something you have made before.
Descriptions can be short. Something like "a pendulum lab where students change length and gravity" is plenty.
It already knows the lesson
You do not need to restate the context. The lesson and the page you are working on are read when the visual is generated, so what comes back fits the material around it rather than being a generic widget on the topic.
While it builds
A visual takes a few minutes. Nothing waits for it: you can carry on editing, move to another page, or close the tab entirely, and it keeps building.
When it lands while you are somewhere else, you get a notification with a link straight to the page holding it.
Publishing while one is still building
Publishing takes a snapshot of the lesson as it stands, so a visual that has not finished would only ever exist on your draft. If you try, you will be warned first. Either wait for it to finish, or publish now and publish again once it is done.
If it fails
Occasionally one does not come out. The block will tell you, and you can describe it again to have another go.
What students see
Students get the finished visual, working exactly as it does for you, in whichever theme they are using. They do not see the description you wrote to create it.