you can do this on debian, too. It’s not specific to the OS – it’s the window manager. Specifically, this kind of window manager is called a tiling window manager.

Basically it just organizes your windows slightly differently. Instead of having them floating around like in Windows, Mac, or traditional desktop environments like GNOME, it tiles them – when you open a new window, it automatically split screens it.

window managers also don’t by default have things like a battery display or a wi-fi applet, like your typical desktop environment does – you have to do that stuff manually by building some sort of status bar (there are various apps that provide status bars).