What is the difference between waxing and waning?

Rob says crescent is when you can see less than half of the moon illuminated. “Gibbous, you attach that to either waxing or waning when you see more than half of the moon illuminated,” he said. Waxing means it's getting bigger while waning means it's getting smaller.

i think that d. wind is the answer.   i missed the question when i answered a. currents.

i thinking chemical change