Use Snap to arrange all your open windows using the mouse, keyboard, or the Snap Assist feature.
Snap with a mouse
Select the title bar of the window you want to snap, and drag it to the edge of your screen. An outline indicates where the window will snap to once you drop it. Drag it to the left or right side of your screen depending on where you want to snap it to.
Snap with a keyboard
Select the window you want to snap and press the Windows Logo Key + Left Arrow or the Windows Logo Key + Right Arrow to snap the window to the side of the screen where you want it to be. You can also move it to a corner after snapping it. With the window selected, press the Windows Logo Key + Up Arrow or the Windows Logo Key + Down Arrow to get it into the desired corner. The window is then in its smallest possible state, which is a quarter of the screen. Then you can use the Windows Logo Key + Arrow Keys to move it wherever you want.
Snap with Snap Assist
Snap Assist appears after you’ve snapped a window but have a lot of available space on your screen. Any other open windows are displayed in that space as thumbnails.
To use Snap Assist, click the thumbnail of the window you want to open in the empty space on your screen. If you have two windows displayed side-by-side, you can resize both windows simultaneously by selecting and dragging the dividing line. Resize the window on one side to the size you want it to be, and then release the mouse button. The other window will resize itself to fit alongside the first one, so you won't have any empty screen space.