What is the difference between "mole" and "Avogadro's constant"?
It's sort of like the difference between "12" and "dozen". Explanation below...
Avogadro's constant is the number of identical particles found in one mole of that substance. So, using the word "mole" in Chemistry is a bit like using the word "dozen" in something like baking. It is a name that has been given to represent a particular number of items, regardless of what type of item we are referring to (as long as they are identical items).
However, when we ask how many objects would be found in that quantity, for "dozen" the answer is 12. For "mole" the answer is Avogadro's constant,