Help system: difference between [Back] and (Back]?

Once you delve into the Codea reference manual you see two Back buttons at the top of the screen. The lower one seems to do what I want (like Back on a web browser); the upper one I can’t quite figure out what it’s trying to do. Can someone explain why there are two Back buttons and how to use them, please?

Edit: The two buttons also have slightly different shapes which I tried to indicate in the subject line.

the more rectangular back (the higher back) goes back to the “page” you were last on and the arrow shaped back (under the rectangular) takes you up a level e.g.

Graphics -->  backingMode( mode ) --> background (from the tab at the bottom of the screen)
pressing the rectangular back will send you back to the backingMode(mode) Documentation
and pressing the arrow shaped back will send you back to the Graphics section

hopefully im not confusing you too much, good luck @Mpark

Thanks, @Dalorbi, but my experience is different. If I follow your path to “background”, the rectangular (upper) Back doesn’t take me back to “backingMode”; instead, it gets stuck on “background”. That is, the screen scrolls as if going to a different page, but it’s stll “background”.
The other Back button does back me out screen-by-screen to the top, at least most of the time. If I mix upper Back and lower Back, Codea sometimes forgets where it started.

following the (back] will almost always work cleanly, ill experiment with both and tell you what i find @Mpark