The purpose of a Container is to group elements inside a shared space and allow you to have better control over those elements inside. Containers can be added both as Tiled or Floating (in the end it's your decision, and both solutions work fine). They can be Horizontal or Vertical. The following screenshots will help you see the difference. First, here's an example of a Horizontal Container:

And here's an example of a Vertical Container:

When you add a Container, it'll be empty. Then, you can drag and drop Worksheets or objects inside ...

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