The Tile Vertical command arranges all windows so they are not overlapping. The tiling algorithm will attempt to make windows taller than they are wide. This is useful for viewing 2 or more files side by side.
Toggle Extend Mode
The Toggle Extend Mode command toggles extend mode on and off. If extend mode is on, then movement commands, such as Cursor Up, Cursor Down, Top of Window, and Go To Line, (to name a few), will cause the current selection to be extended to the new location. If extend mode is off, then the movement commands simply put an insertion point at their destination.