This document defines key concepts related to solutions and solubility. It explains that a solution is a homogeneous mixture of two or more substances, with the solute dissolved in the solvent. Aqueous solutions use water as the solvent. The solvation process involves the solute and solvent particles separating and then mixing together, with energy released. The solubility of a substance depends on how much can dissolve in a given amount of solvent at a given temperature, with saturated, unsaturated and supersaturated solutions defined based on this amount dissolved.