Molarity is no of moles in a given volume of solution whereas molality is no of moles in 1 kg of solvent.

Molarity :- It is defined as the number of moles of solute in 1 litre of the solution.

Molality :- It is defined as the number of moles of solute present in 1 kg of solvent.

molarity:-no.of moles of solute dissolved in 1 litre solution

molality:- no.of moles of solute dissolved in 1 kg solvent