No, i3 is a full, graphical, window manager, for graphical applications.

https://i3wm.org/

As GP said, by default, it's automatic, so there are no pre-defined "zones". But it can be scripted to do quite a lot of things.

Not at all. It's a tiling window manager with workspaces, for all your applications. Terminals, web browser, audio settings, etc.

Personally I run 10 workspaces, named, e.g. 1:Firefox work, 2:vim, 3:tmux+vim, 4:terminals, etc. I even have a workspace designated to "wasting time", tiled reddit, hn, youtube, etc.

Each workspace always have the same apps, tiled in the same way, so I always know where to find what. It's very efficient.

Maybe you're thinking of tmux which splits your terminal into multiple panes and can look similar.