CanvasLayer node or Control node for UI container?

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:bust_in_silhouette: Asked By ken

Learning game UI, I noticed that some examples use CanvasLayer node as the UI container but some other examples use Control node for the same purpose.

With a little bit of Unity experience, I remember Unity uses the Canvas component which stretches to the entire viewport for UI and it always displays on top of everything. Is CanvasLayer node of Godot is similar to the Canvas component of Unity?

I wonder why some tutorials use Control node as the UI container instead of CanvasLayer node. I noticed that UI under Control node does not always display on top of all contents.
I saw tutorials that use CanvasLayer node for HUD (hp, mp, score, etc…), but others use Control node for start menus (Start, Option, Quit, etc…). is it a common practice in Godot? Is there any reason or use-case to use Control node instead of CanvasLayer node?