GIMP is an acronym for GNU Image Manipulation Program. It is a freely distributed program for such tasks as photo retouching, image composition and image authoring. GIMP is also available on most platforms, including PC and Mac.
It has many capabilities. It can be used as a simple paint program, an expert quality photo retouching program, an online batch processing system, a mass production image renderer, an image format converter, etc. You can download it from their website here: www.gimp.org
These 30 videos will show you how to use the GIMP, just select which video you’d like to watch from the dropdown and it will appear in the window below: