Moving, hiding, or inverting a selection
You can move a selection border around an image, hide a selection border, and invert a selection so that the previously unselected part of the image is selected.
To move a selection border:
- Using any selection tool, select new selection
from the options bar, and position the pointer inside the selection border. The pointer changes to indicate that you can move the selection 
. - Drag the border to enclose a different area of the image. You can drag a selection border partly beyond the canvas boundaries. When you drag it back, the original border reappears intact. You can also drag the selection border to another image window.
Original selection border (left), and selection border moved (right)
To control the movement of a selection:
- To constrain the direction to multiples of 45°, begin dragging, and then hold down Shift as you continue to drag.
- To move the selection in 1-pixel increments, use an arrow key.
- To move the selection in 10-pixel increments, hold down Shift, and use an arrow key.
To hide or show selection edges:
- Choose View > Extras. This command also shows or hides (Photoshop) selection edges, grids, guides, target path, slices, and annotations, or (ImageReady) selection edges, layer edges, grids, guides, smart guides, slices, auto slices, image maps, and text selections. (See Working with Extras.)
- Choose View > Show > Selection Edges. This toggles the view of the selection edges and affects the current selection only. The selection edges reappear when you make a different selection.
Do one of the following:
To select the unselected parts of an image:
Choose Select > Inverse.
You can use this option to select an object placed against a solid-colored background. Select the background using the Magic Wand tool and then inverse the selection.