(a) A solution in which at a given temperature, no more solute can be dissolved by the solvent is called a saturated solution. The concentration of such solutions is the maximum at a given temperature.

To illustrate this, take a glass or a beaker and add some common salt to it. Fill the beaker with water and stir it well. One now gets a salt solution. Continue adding salt slowly to the beaker along with stirring. At some point of time, the solution reaches a state where even though salt is added and stirred, some of the salt stays undissolved. Then one can say that the solution has reached its saturation level at that temperature.

(b) A solution in which at a given temperature, more solute can be dissolved by the solvent is called an unsaturated solution. Unsaturated solutions can be made saturated by adding more solute to it. In the activity mentioned in (a), the solution obtained in the beginning is an unsaturated solution.

(c) The suspension is a heterogeneous mixture of 2 or more components. The particles forming the suspension are visible to the naked eye. In this mixture, the solute particles do not dissolve in the solvent, instead, they remain suspended in the solvent medium. When left undisturbed, the solute particles tend to settle down at the bottom of the container.

Eg: Mixture of sand and water forms a suspension.