Story lines are the backbone of any narrative, and can be broken down into two components: arcs and plots. An arc is a character's journey throughout the story, while a plot is the sequence of events that make up the story. Arcs are typically shorter than plots, and focus on the development of a single character or group of characters. Plots, on the other hand, are longer and encompass the entire story, including the introduction, rising action, climax, and resolution. Together, arcs and plots form the story lines that make up a narrative.