How to change screen resolution while in X-Windows

xrandr can change display orientation, resolution and various other screen settings in X-Windows.

SZ:   Pixels          Physical       Refresh 1   800 x 600    ( 347mm x 260mm )   85 Current rotation - normal Current reflection - none Rotations possible - normal Reflections possible - none Setting size to 0, rotation to normal Setting reflection on neither axis
 * To see avalable options set in /etc/X11/xorg.conf
 * Execute: xrandr --verbose
 * output:
 * 0  1024 x 768    ( 347mm x 260mm )  *85


 * To change the display resolution to 800x600
 * Execute: xrandr -s 800x600
 * An alternative way to change settings it to use the number presented by ''xrandr --verbose
 * Example: xrandr -s 0
 * For: *0  1024 x 768    ( 347mm x 260mm )  *85

other common display resolutions are
 * 640x480
 * 800x600
 * 1024×768
 * 1280×1024
 * 1600×1200
 * See List_of_common_resolutions

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