In an interview I heard a while back, actor Tommy Lee Jones talked about how he had to have a little prop around to work with because he always want to have some business going on, if you watch him in a movie, he’s usually fiddling with something. The business he referred to is known as Stage Business.
Stage Business is the little actions preformed by actors while they deliver their lines or are on the side of the main action. These actions transform them from actors standing around saying lines into characters. The business can range from how a character holds their coffee cup to the way they interact with another actor in the background. In real life people do all kinds of things while they talk, they sip on a coffee cup, push paper clips around their desk, they reach out and touch the person they are with, or not. These actions are the forms of non-verbal communication that add subtext and meaning to a conversation. They tell us what’s going on inside the person’s head.