Stop motion is an animated-film making technique in which objects are physically manipulated in small increments between individually photographed frames so that they will appear to exhibit independent motion when the series of frames is played back as a fast sequence. Dolls with movable joints or clay figures are often used in stop motion for their ease of repositioning. Stop-motion animation using plasticine figures is called clay animation or "clay-mation". Not all stop motion, however, requires figures or models: stop-motion films can also be made using humans, household appliances, and other objects, usually for comedic effect. Stop motion using humans is sometimes referred to as pixilation or pixilate animation.
The term "stop motion," relating to the animation technique, is often spelled with a hyphen as "stop-motion." Both orthographical variants, with and without the hyphen, are correct, but the hyphenated one has a second meaning that is unrelated to animation or cinema: "a device for automatically stopping a machine or engine when something has gone wrong" (The New Shorter Oxford English Dictionary, 1993 edition).
Stop motion should not be confused with the time-lapse technique in which still photographs of a live scene are taken at regular intervals and then combined to make a continuous film. Time lapse is a technique whereby the frequency at which film frames are captured is much lower than that used to view the sequence. When played at normal speed, time appears to be moving faster.