A solution is a homogeneous mixture of two or more substances, with a solute that dissolves in a solvent. Water is a universal solvent that can dissolve many other substances like salt or sugar due to its polarity. The concentration of a solution describes how much solute is dissolved in the solvent, and can be saturated, unsaturated, or supersaturated depending on whether it contains the maximum, less than maximum, or more than maximum amount of solute dissolved. Not all solutes are miscible and able to dissolve in a given solvent.