Molality is a measure of the concentration of a solute in a solution. It is defined as the number of moles of solute per kilogram of solvent. This means that if you have a solution with a certain amount of solute, you can calculate its molality by dividing the moles of solute by the mass of the solvent in kilograms. Molality is particularly useful in situations where temperature changes occur, as it does not change with temperature. This is because it is based on mass rather than volume, making it a reliable measure for studying properties like boiling point elevation and freezing point depression in solutions.