What is the meaning of the term “rate of change”?

Rate of change describes how much one quantity changes compared to another. For example, if you’re driving, your speed is a rate of change—how far you go in a certain amount of time. In calculus, the derivative measures this rate at a specific point. It tells us not just that something is changing, but how fast it’s changing right now. Rates of change appear in science, economics, and everyday life. They help us understand trends, such as how fast prices are rising or how quickly a disease is spreading, making them key to analysis and prediction.