To display two buffers vertically, you can use:
:vsplit #
or short version
:vs #
To reorganize a layout from horizontal to vertical, you should use:
<CW>K : move the current windows up to the horizontal split
<CW>J : move current windows down to horizontal split
<CW>H : move the current window to the left using vertical splitting
<CW>L : move the current window to the vertical split rig
See :help windows.txt details
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