Aristotle's three unities of drama are unity of time, unity of place and unity of action. The three unities are derived from Aristotle's work "Poetics," and they represent neoclassical concepts.
The unities are meant to focus on verisimilitude in drama, which requires that the drama takes on a closer to truth approach and represents what could only be possible in real life. Unity of time demands that plays should be confined to a short period of time or within 24 hours. For example, "Oedipus Rex" occurs in an hour and a half. The second Aristotelian unity, unity of place, emphasizes the use of a single locale, such as one city or town. In addition, unity of action limits the play to a single plot.