An action the behavior that an individual had and whether or not it was willfull or out of one's control.
Sherlock Holmes solved the theft of the Bruce-Partington plans, an action for which Queen Victoria presented him with an emerald tie pin. (TNG: "Elementary, Dear Data")
According to the Dictates of Poetics by T'Hain of Vulcan, a character's actions must flow inexorably from his or her established traits. (VOY: "Worst Case Scenario")