The command adds a guide to the image. For more information about guides, see the glossary entry on Guides.
               
             | 
            Tip | 
|---|---|
| 
               You can add guides to the image more quickly, but less accurately, by simply clicking and dragging guides from the image rulers and positioning them where you would like.  | 
          
When you select , a dialog opens, which allows you to set the Direction and Position, in pixels, of the new guide more precisely than by using click-and-drag. The Direction may be Horizontal or Vertical. The coordinate origin for the Position is the upper left corner of the image.