Selections and masks are subtly different, and the ‘parametric’ masks in non-destructive editors give more flexibility than ever.
Selection
A way of separating out a specific part of a picture for adjustments. Selections can be made using a variety of tools such as a rectangular or circular marquee, a magic wand or a selection brush. When the selection is made, it has an animated, dashed outline sometimes called ‘marching ants’.