Stop motion photography works by setting a scene and then taking a picture of it (with either a manual or digital camera). The scene is then altered slightly and another shot is taken. This process continues until the scene has gone through its entire action sequence.
When each of the single images is put together, the objects in each shot appear to move. Think of how a flip book is composed: an illustration is slightly altered on each page, so that when it is quickly flipped, the illustration appears to move.
This technique is most commonly used in film and video production. Famous examples being the work of Aardman studios like Wallace and Gromit or Chicken Run. Bob the Builder also uses this technique.
However, this technique can also be done with still photography using the same methodology. Instead of combining the shots to create a stop-motion film you use an image application like 'ImageReady' or 'Fireworks' to create a series of layers with each shot of the sequence being one of the layers.
You can then create your stop-motion animation by saving the layered image as an 'animated gif'.
By doing this the layers are preserved and when the image is embedded into a web page it cycles through the layers to give the appearance of movement.
While this technique has limited applications it can be used to create some amazing results. Below are six images by the same photographer illustrating just how creative you can be using this method of animation.