This video teaches how to interpret and analyze graphs to describe the rate of change in a function. Two different graphs are used to tell stories about water levels in a bathtub and the classic race between a tortoise and a hare. Through these examples, viewers are shown how to identify and understand the slope and linear relationship of a graph, as well as how to interpret the outputs to tell a story. The lesson also addresses common misunderstandings about graphs, such as horizontal lines and negative slopes.