Upon first working with the anchors and pivots system in unity I got confused, things didn’t end up where I wanted them, and I didn’t understand what the UI was trying to tell me.
I made a simplified example to show some things that I didn’t immediately catch onto.
Anchors allow you to not only define how the UI change as screens resize (and this is super important), but they also change the relative position of the element from its anchor, and that’s how its position is defined.
In the pictures above the only thing I changed was the Rect Transform’s anchors (click the square picture that demonstrates its current position and you can select this, this was not obvious to me at all.
Also this may not be obvious to you yet, but nested objects automatically scale and transform based on the parent, so nesting panels is the way to go (similar to nested divs/spans in a web context.)