This document defines and describes mixtures and solutions. It explains that mixtures are made of two or more substances physically mixed together and can be either heterogeneous, with visible particles of different substances, or homogeneous, appearing uniform throughout. Solutions are defined as homogeneous mixtures formed when one substance dissolves in another. Key solution terms are also defined, such as solute, solvent, solubility, soluble, and insolute. Solutions can be dilute, with little solute, or concentrated, with a lot of solute.