Each window has two modes: Floating and tiling. Tiling is explained here Floating mode allows you to freely move and resize any window.
Activating floating mode
To make a window float, press Super + Shift + Space. Alternatively you can just move the window (see “Moving Windows” below) and it’ll go into floating mode automatically. To make a window return to the tiling layout, either do Super + Shift + Space again or drag it to the top of the display and let go of it just like with regular desktop environments.
To move a floating window, hold down the super key and move it around using the left mouse button. You can also move it by dragging out its title indicator like on regular desktop environments. This will work no matter where the window is, the cursor will be warped to the window.
Super + Right mouse button resizes a window. The cursor will snap to the nearest corner/edge and resize from there.
Hovering the mouse near the outside border of the current floating window (green border) will make the cursor turn into a cross-hair. You can then resize the window by left click dragging the border or move it by dragging the top.
The window-drawing feature can also be used to resize and move windows
Dragging a window onto a tag number and letting go of it will move it to that number and follow it there. Holding shift while letting go will move it there but keep the view focused on the current tag. Dragging the green indicator on the tag numbers will move the currently active window to that tag number. Holding shift while letting go will follow the window there.
Dragging a window to the side of the screen and letting go of it with the shift key held down will snap it to half of the screen like on traditional desktop environments.
Dragging a window to the left/right side of the screen and letting go of it will move it to the adjacent tag. The lower third of the screen will move it there and not follow it, anything above that will follow the window to that tag.