What is happening to the moon when it is in waxing?
The illuminated parts get bigger during waxing.
When the moon is waxing it means that the illuminated part is getting bigger from one day to the next in the first 2 weeks after new moon.
At full moon it is fully illuminated, where after it starts waning (getting smaller) for the last two weeks before new moon.
At full moon, the whole of the illuminated side faces towards the moon, while at new moon the whole of the illuminated surface is facing away fro the earth.
Waxing and waning occurs between the two extremes.