What is the difference between a change in demand and a change in quantity demanded?

What is the difference between a change in demand and a change in quantity demanded?

 

What is the difference between a change in demand and a change in quantity demanded? Supply and quantity supplied? Give an example of what could cause a change in each? Explain how a freely operating market could eliminate shortages and surpluses.(Go through the steps in the process). What role do prices play in this process? […]