Molarity:
Molarity is a unit of concentration used in chemistry to measure the number of moles of solute present in one liter of solution. It is denoted by the symbol "M" and is expressed in moles per liter (mol/L). Molarity is commonly used in laboratory experiments and is useful in determining the volume of a solution needed to react with a given amount of a solute.

Molality:
Molality is another unit of concentration used in chemistry to measure the number of moles of solute present in one kilogram of solvent. It is denoted by the symbol "m" and is expressed in moles per kilogram (mol/kg). Molality is particularly useful in calculations involving colligative properties of solutions, such as boiling point elevation and freezing point depression.

Normality:
Normality is a unit of concentration used in chemistry to measure the number of equivalents of a solute present in one liter of solution. It is denoted by the symbol "N" and is expressed in equivalents per liter (eq/L). Normality is used for acid-base reactions and redox reactions, where the stoichiometry of the reaction is based on the number of acid or base equivalents involved.

Differences:

1. Definition:
Molarity is the number of moles of solute per liter of solution.
Molality is the number of moles of solute per kilogram of solvent.
Normality is the number of equivalents of solute per liter of solution.

2. Dependence on Temperature:
Molarity and Normality are temperature-dependent, as the volume of a solution changes with temperature.
Molality is temperature-independent, as it is based on the mass of the solvent.

3. Use in Calculations:
Molarity is commonly used in stoichiometric calculations and determining the volume of a solution needed for a reaction.
Molality is used in calculations involving colligative properties and is more accurate for determining concentration in reactions involving changes in temperature and pressure.
Normality is used in acid-base and redox reactions, where the stoichiometry is based on acid or base equivalents.

4. Applicability:
Molarity is widely used in general laboratory experiments and calculations.
Molality is particularly useful in determining the effect of solute concentration on colligative properties of solutions.
Normality is specifically used in acid-base and redox reactions, where the stoichiometry involves acid or base equivalents.

In summary, molarity is based on the volume of the solution, molality is based on the mass of the solvent, and normality is based on acid or base equivalents. Each unit of concentration has its own specific applications and is used in different types of chemical reactions and calculations.