This is Tiles

Snap windows by dragging

Drag a window to one side of the screen and it'll get automatically resized and positioned in place. We call this: “snapping”.

For example: try to drag a window to the left of the screen and it'll take half the space. Or maximize a window by dragging it all the way up.

You can also snap windows by using convenient keyboard shortcuts. And yes: they can be customized!

Don't worry if you don't remember them, just click on the Tiles icon in the status bar.