Photo-Manipulation Photo-manipulation is the art of altering an image to express what you want, rather than what the original image may have displayed. It is done for deceitfulness and artistic reasons. Photoshop is the most popular application used for this process.
Illustration Illustration is simply the creation of an image using a range of various mediums. You could paint, use a computer, draw in pencil or pen, use collage and so on. Illustrations generally have narratives or purpose, they tell stories, they sell products, they convey information. They are all around us on cereal boxes, magazine ads, billboards, clothing and so on and are becoming a very useful medium to communicate an idea without using photography, video or text.