Mole (mol) the number equal to the number of atoms in exactly 12 g of 12C.
This number called Avogadro's number: 6.02214 x 1023 (6.022 x 1023).
The term mole is number of items (e.g.: atoms, molecules, .... ) For example: Dozen of eggs means
12 eggs and mole of eggs means 6.022 x 1023 eggs
Mass of 1 mol 12C = 12 g
The mass of 1 mol of atomic mass unit is 1 g
The mass of 1 mol of an element is equal to its atomic mass in gram