Corner bead is a finishing profile fitted to drywall corners to create a defined edge and help protect it from everyday knocks. It is covered with joint compound before priming and painting, so it normally becomes part of the finished wall surface. Paper-faced metal bead is one type, and different profiles are available for different corner details.
When discussing wall finishes in basement renovation planning, review the proposed corner profile alongside the room’s other details. Ask which product and installation method are intended, particularly at exposed corners in busy areas. Before painting, check that the finished edges look straight and the compound transitions smoothly into the wall. Corner bead shapes and reinforces the finish; it is not the framing behind the wall.