It affects the conduction of heat in a substance, and more importantly, the ability of a substance to absorb heat energy.
Specific heat is the amount of heat needed to raise the temperature of a certain mass (usually one gram) by 1 degree Celsius
Differences in specific heat for different substances means that different materials can be used for heat conduction or insulation, as desired. They can also be used as “heat sinks” for storage of energy or dissipation of excess thermal energy from a process – such as the heat sinks used on computer CPU chips and other components. It is an important factor in the selection of materials for refrigeration systems and their design.