Gimp is a photo editing program that includes tools like the move, crop, fuzzy, paths, scale, blend, text, pencil, airbrush, clone, blur/sharpen, smudge, dodge/burn, and mask tools. It allows users to select areas of an image using selection tools, create new layers, and cut, copy, and paste images or parts of images. The document also discusses how to change an old image into a new image using Gimp.