The word "animation" means, essentially, the process of bringing a non-living thing to life. Film animation has been trying to achieve that feat for more than a century. The earliest examples of film animation were created around the turn of the twentieth century. Filmmakers continued to develop new animation techniques throughout the century, ensuring that the genre remained consistently fresh and popular to the present day.
Traditional animation relies on techniques that link together a series of still images. The objects in the images change slightly from image to image. When the images are displayed in rapid succession, the objects appear to move. Stop-motion animation uses images of actual objects. The images are photographed, moved slightly, and then photographed again to produce the animation sequence. Hand-drawn animation uses a series of minutely varying drawings instead of real objects to produce the same effect. Digital animation employs computer-generated models, motion and effects. Occasionally, films combine animation with live action, overlaying live-action footage with animated elements so that animated characters can appear to interact with real actors.
Traditional hand-drawn animated films were extremely popular in the first half of the twentieth century, when Walt Disney Studios produced a number of very successful full-length animated films that featured high-quality animation and memorable musical scores. After a lull in popularity, animation had a resurgence of mainstream commercial success late in the century. 1995's Toy Story, produced by Pixar studios and distributed by Disney, ushered in the digital-animation revolution.
Although animated productions aimed at adult audiences have been successful on television, the majority of mainstream animated films produced by American studios have been targeted at younger audiences. The most commercially successful films, however, have appealed to audiences of all ages. Many Pixar films, for example, have been more able to pull in viewers from older age groups than animated films have historically been able to do.