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.
Molarity cheat sheet for homework
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.