Molarity is a measure of the concentration of a solute in a solution, or of any chemical species in terms of amount of substance in a given volume.
This is another way to express concentration, but instead of volume, it uses mass. It's defined as moles of solute per kilogram of solvent.
Normality: This measures concentration in terms equivalent weight per liter. It’s often used when discussing acid-base reactions.
This is what gets dissolved into something else. In our lemonade example, the powder would be the solute.