Heat capacity is a term that pertains to the amount of heat required to raise the temperature of a substance by a certain degree. This property is also referred to as thermal capacity, heat reservoir, or thermal inertia. Another synonym commonly used is specific heat capacity, which is defined as the amount of heat required to raise the temperature of a unit mass by a given degree. Additionally, heat retention, heat absorption, and heat storage can also be synonymous with heat capacity. The accurate understanding of these terms is crucial in thermodynamics, materials science, and engineering, and can help develop efficient heating and cooling systems to meet energy demands.