Clipping Path
A vector path used to isolate part of an image for manipulation or compositing.
In practice
A clipping path is a closed vector outline drawn around the part of an image you want to keep, so everything outside it is hidden. It is common in catalog and packaging work: a shoe photographed against a gray backdrop gets a precise path along its outline so it can sit on a white page or over a colored panel. Because the path is a vector shape, its edge is crisp, which suits hard-edged products better than hair or fur.
Often confused with Mask
A clipping path is always a hard-edged vector outline; a mask can also hold soft, partial transparency for fuzzy edges.
Try this
Trace a simple object in a photo with a pen or path tool, then place it on a new colored background.