Animation is a graphic representation of drawings to show movement within those drawings. A series of drawings are linked together and usually photographed by a camera. The drawings have been slightly changed between individualized frames so when they are played back in rapid succession (24 frames per second) there appears to be seamless movement within the drawings.
Early animations, which started appearing before 1910, consisted of simple drawings photographed one at a time. It was extremely labor intensive as there were literally hundreds of drawings per minute of film. The development of celluloid around 1913 quickly made animation easier to manage. Instead of numerous drawings, the animator now could make a complex background and/or foreground and sandwich moving characters in between several other pieces of celluloid, which is transparent except for where drawings are painted on it. This made it unnecessary to repeatedly draw the background as it remained static and only the characters moved. It also created an illusion of depth, especially if foreground elements were placed in the frames.
Walt Disney took animation to a new level. He was the first animator to add sound to his movie cartoons with the premiere of Steamboat Willie in 1928. In 1937, he produced the first full length animated feature film, Snow White and the Seven Dwarfs. Although anyone could do a simple animation, the really great animations came from highly gifted individuals.
In the 1960s two scientists from Bell Labs developed the world's first computer animations. Messrs. Zajac and Knowlton's achievements were in the area of abstract and texture patterns. Further research in the use of computers for graphic output helped the progress the field of computer animation.
Since the 1970s, computer animation has grown as computers improved and new techniques for manipulating pictures were discovered. Companies specializing in generation of computers animation have been founded, including names such as MAGI, Lucasfilm Ltd.