A character's motivations are the reasons behind his or her words and actions. As readers, we want to know those reasons because they help us better understand both the character and the plot of a story.

Let's look at an example. We're reading a scene in a story in which a man in dark clothing is standing outside the window of a house. He glances around furtively, edges open a window, and climbs inside. We might assume that this man is a burglar who intends to rob the house. Any witnesses within the story might think so, too, including a neighbor down the street who happens to be looking out her window at just that moment.

However, as we continue the story, we read the following:

John couldn't believe he had forgotten his keys. He was embarrassed but extremely relieved to find that unlocked window. Since he had just moved into his new neighborhood, he was also pleased that no one had seen him, or so he thought. He chuckled as he reflected on how his new neighbors would respond to the show he had just put on outside.

The character's motivations make all the difference for both the character himself and the story's plot. John isn't a burglar at all; he's just forgetful and, thankfully, resourceful. That neighbor down the street, however, hasn't yet discovered John's motivations, and she calls the police, who show up a John's house a while later, only to laugh heartily when they learn what had happened. John decides that he owes his new neighbor an explanation, and he brings her a plate of cookies the next day. John's motivations have driven the plot of the story, setting up both its conflict and its resolution.