In post-production of any kind of image-related material, compositing is the term used to refer to the process of creating complex images by combining multiple (and possibly simpler) images (possibly from many different sources) to produce the final image or set of images. Digital post-production work builds on the same post-production concepts as did still photography and motion pictures and video before. Each new techology has added new ways of doing the work, and this has fed back into how later artists do older things.
Today the materials will be grounded in doing compositing work within the PhotoShop® environment, but please do not make the mistake of thinking this is something exclusive to PhotoShop®. All general-purpose graphics post-production tools allow you to do compositing work. Producers of media live and die by their post-production work, and the idea of compositing simple graphics into complex experiences is an essential conceptual tool in building effective visual presentations.
The key to getting good at this work is to practice it a lot. Spend time in the Lab, mess around with making some funny image(s) by putting togeether multiple simpler graphical elements (parts of other pictures, text, cartoon images, etc.).
Materials on using layers in PhotoShop® for image compositing.
Take a look at these propaganda images. Now find a picture of your instructor, and create a composite image which places your instructor in a situation which is not real. In other words, create a propaganda image which combines an image or images of your instructor with other graphic elements to create some final composite image which presents a message or narrative which never actually happened.
Be ready to present very briefly about this image at the next class meeting. Images will be judged arbitrarily by the instructor or whatever random person they kidnap from the hallway. All decisions of the judge or judges are final, and complainers will be shot out of cannons.The winning design person will receive one Get Out Of Jail Free card, good for one in-class or at-home assignment.