PHOTO Layer MAsking
Layer masking is a reversible method of concealing a portion of a layer. This gives you more editing options than wiping or deleting a portion of a layer permanently. Layer masking can be used to create image composites, chop off elements for use in other documents, and restrict alterations to a portion of a layer.
ALPHA CHANNEL MASKIng
Alpha channel masking is a technique for separating pictures similar to layer masking, but it is preferable in terms of file size, as it is smaller, making the downloading or uploading procedure more flexible. Actually, after clipping path, image masking, and other techniques have been used to extract the picture from the backdrop.