A solution is a homogeneous mixture. One substance (the solute has dissolved in another (the solvent). Although the term solution usually calls to mind a liquid solvent, both solute and solvent can be in any of the three states of matter. For example, a solid can be dissolved in a liquid (salt water), a liquid dissolved in a liquid (rubbing alcohol), a gas dissolved in a liquid (carbonated beverages), or a solid dissolved in another solid (alloys). As for terminology, if the solution is liquid and the solute is solid or gas, the liquid component is usually called the solvent. If both solute and solvent are liquids, the component present in the larger amount is usually considered to be the solvent.

Remember that a solution is homogeneous. Only one phase or physical state is visible. A cloudy liquid is not a solution, for the cloudiness means that a substance insoluble in the solvent has been suspended in the solvent. Milk is a suspension, not a solution. Tea is a solution.