In the book ‘The Technique of Film Animation’ John Halas brings up the importance of continuity and I quickly made this animation to help better understand exactly what it means. 

The animation is a series of four images, however, the lines depicting the form vary greatly from one image to the next. If the sequence had continuity the images would flow seamlessly into one another. That being said, I think a case can be made for a lack of continuity in certain cases.

For more on this see my posts on A-Ha’s Take on Me and Roobarb and Custard