 Each of these sequences might further contain sub-sequences; for example the robbery sequence might consist of an entry sequence, a safe-cracking sequence, and so on.The sequence is one of a hierarchy of structural units used to describe the structure of films in varying degrees of granularity.Analysed this way, a film is composed of one or more acts; acts include one or more sequences; sequences are divided into one or more scenes; and scenes may be thought of as being built out of shots (if one is thinking visually) or "beats" (if one is thinking in narrative terms).