|From: Found in Mom's Basement|
"Beyond the world of storytelling, plot is defined as a secret scheme to reach a specific end. Or it’s a parcel of land. Or it means to mark a graph, chart, or map: the plotting shows us what has changed; our ship is headed this way. To a writer (me) interested in (obsessed with?) plot-making, all of these are significant definitions. The lessons abound.
Arc is tied into notions of plot because both concern action, event, and change as they relate to character. I want to say that arc is the structure on which plot hangs. And now, a second later, I want to say that arc is the unfolding of plot, the specific path that events take to enable a character to move through a story. And now, two seconds later, I want to say that if plot is the what and the why, then arc is the how. As you can see, I’m still working all this out in my mind."
— Edan Lepucki, The Millions