A working definition of animation is practise, is that it is a film made by hand, frame-by-frame, providing an illusion of movement which has not been directly removed in the conventional photographic sense.
'If it is the life-action film's job to present physical reality, animated film is concerned with metaphysical reality - not how things look, but what they mean.' (Hoffer, 1981 : 3)
To animate, and related words, animation, animated and animator all derive from the latin verb animare, which means 'to-give-life-to' and within the context of the animate film, this largerly means the artifical creation of the illusion of movement in inanimatelines and forms.