Press and hold the left mouse button on a window’s title bar
Drag the window to the left or right side of the screen until you see an outline
Release the mouse button to snap it into place
Click or select the other window you want to use
Drag it to the opposite side of the screen until it snaps
Use the keyboard shortcut: press Alt + [ to snap the active window left
Use the keyboard shortcut: press Alt + ] to snap the active window right
If you don’t see snap options, open the Overview screen (Search + Esc or swipe up with three fingers)
Drag one window to the left or right area in Overview
Select the second window and drag it to the opposite side in Overview