Concentration refers to the amount of a substance (solute) present in a certain volume of solution.
Molarity: This is a measure of concentration in chemistry, defined as the number of moles of solute per liter of solution.
Solvent: This is the substance that dissolves another substance (the solute). In our lemonade example, water is the solvent.
Solute: This is what gets dissolved in a solution. In our analogy, the squeezed lemons represent the solute.