Masks are great aids in editing photos and artwork because they allow you to work on or edit specific areas of an image. As mentioned earlier, a mask isolates an area of an image by protecting it from editing. For example, if you want to apply a filter effect or color to only a portion of an image, using a mask is a perfect solution. You can produce two types of masks in Photoshop: layer masks and vector masks. Whenever you need to create a clean, sharp-edged shape for use as a mask, such as for geometric shapes or original drawings, the Vector Mask command is the one to use.
For more about the differences between layer masks and vector masks, read “Layer masks vs. vector masks,” later in this chapter.