Distillation is a process that separates compounds with different boiling points in a mixture. The substance with the lowest boiling point will evaporate faster compared to the other. Example, a mixture of salt(NaCl) and water. When heat is supplied to the mixture, water evaporates leaving behind salt since water has a lower boiling point compared to NaCl.
Water's high heat capacity is a characteristic produced by hydrogen bonding between water molecules. Specific heat is determined as the quantity of heat one gram of a substance need to absorb or lose to substitute its temperature by one degree Celsius. For water, this amount is one calorie or 4.184 Joules