Definition - What does Heat Capacity mean?
Heat capacity is the term given to a measurement of the amount of heat within a defined system that is required to to increase temperature within the system by one percent. The heat capacity of a system is usually measured in joules or calories. It is expressed in units of thermal energy per degree in temperature. A calorimeter is required to measure heat capacity.
Safeopedia explains Heat Capacity
Measuring heat capacity is important in calorimetry, which is used to measure the heat effect of a process. This process could include physical or chemical changes, such as with evaporating, melting, dehydration, acid base neutralization, dissolving, crystallization and solid-state chemical reactions. Calorimeters are instruments that can determine heat effects within them by directly measuring temperature.