The selection marquee is visible by default. When you work with a selection, it is sometimes helpful to hide the selection marquee temporarily without disabling the selection. For example, you may want to see the results of pasting a selection or of feathering a selection’s edges.
When you hide the selection marquee, it does not deselect or clear the selection. The tools and commands you use while the selection marquee is hidden apply only to the selected area.
You can also hide or display the selection marquee by pressing Ctrl + Shift + M.