With Split View, you can fill the screen on your Mac screen two apps or windows side by side.  You do not have to manually move and resize windows.

How to Enter Split View

In macOS Catalina or later you need to do the following:

 

  1. Move your pointer to the left hand corner of you screen and hover over  the full-screen button or simply click and hold the button.
  2. When prompted choose ”Tile Window to Left of Screen” or ”Tile Window to Right of Screen” from the menu. The window will then fill that side of the screen.

     

    3. Then click a window on the other side of the screen to start using both windows side by side.

    That is it you can now work in Split View with two windows side by side.