On: Firefox 89 – Another redesign, another rollercoaster

[yongjik]

Huh, they detached the tabs from the rest of the window?

A "tab" is literally a small thingy attached to the rest of the page so that you can quickly open it up if you want to, like this: https://www.google.com/search?q=file+folder+tabs&tbm=isch

I see no point in detaching the tab, other than obscuring the visual metaphor and making it harder to understand. Designers these days...