The fourth dimension is commonly understood as time, complementing the three spatial dimensions. To locate an event or object, one must specify its position in three dimensions and the time in the fourth dimension. This concept is illustrated by the analogy of giving directions that include a time reference, emphasizing that events are tied to specific moments. The discussion highlights that dimensions serve as parameters to describe events, with time being crucial for pinpointing when something occurs. Overall, understanding dimensions is essential for grasping the nature of the universe and its expanding framework.