Using burning for photo restoration
Burning is a term carried over from when photographers in the darkroom would keep exposing the highlights on a photo to get some tone into an otherwise white area. Burning in photo restoration can be used to darken blacks, or reduce highlights from being too bright.
Photoshop offers many ways to burn an image from a simple tool from the tools palate to adding a whole new layer to burn on an overlay so the original image is untouched and any adjustments can be made without having to start over.

Photo restoration using the burn tool