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.