terminology - What is the difference between molarity and concentration?

I learned these two words in school but still I don't understand what the difference is between them. From my understanding, molarity and concentration means the number of moles in a certain solution. So, what is the difference between the two?

Answer

Concentration is any measurement of the quantity of a solute that is present per unit of solution (in general, there are exceptions like moLality, which measures the number of moles of solute per kilogram of solvent).

Molarity is just one way to express concentrations, which, more specifically, is the number of moles of solute per liter of solution.

But you can give values for concentrations in many different ways, like for example, grams of solute per liter of solution, percentages (grams of solute divided by the grams of solution multiplied by 100), etc.

You can find a wide range of ways of measuring concentrations, including molarity here