What is a saturated solution?
Neither of the previous answers have defined a saturated solution, and would properly be rejected by an examiner. Saturation defines an EQUILIBRIUM condition.
A saturated solution is a solution in which the concentration of the SOLUTE is equal to that concentration that would be in equilibrium with UNDISSOLVED solute. As for any equilibrium we would normally specify a temperature (because at higher temperature, the solvent could probably dissolve more solute).
So for a water soluble salt,
We would probably also specify a temperature, and we could write the equilibrium condition as :
When the ion product (i.e.
These definitions are very poorly understood at undergraduate level, and I urge you to consider them and test your understanding. I reiterate that saturation defines an equilibrium condition, that has been measured for many salts at various temperatures.