If you have a lot of salt in the water then it is a concentrated solution which we would express with a large molarity. So if you have a glass of salt water, you have a solution of water where the water is the solvent and the salt is the solute. Together a solute and a solvent are called a solution. A solvent being a liquid into which something is dissolved into, which is referred to as the solute. Concentration being how much of a substance is in a given volume. Molarity is a unit of concentration, with units of moles of solute/ liters of solvent. So it's more convenient to use moles of atoms instead of saying 6.02214076 x 10^(23) atoms each time we do a calculation. We use such a large number in chemistry because atoms are so small that having even a small amount of atoms like a gram could already be a mole of atoms.
So a dozen eggs is 12 eggs, a dozen people is 12 people, a dozen atoms is 12 atoms. In the same way that a dozen of something is 12 particles.
It is defined as an Avogadro's number of particles, or 6.02214076 x 10^(23) particles. Molarity and moles are measuring different things and hence have different units.Ī mole is the unit for the amount of substance, or how much of something there is.