Having a "high specific heat" means that a substance requires a large amount of heat energy to raise the temperature of a given amount of that substance by one degree Celsius (or one Kelvin). In other words, materials with high specific heat can absorb or release a significant amount of heat without experiencing a substantial change in temperature. Specific heat capacity is an intrinsic property of a material, usually expressed in joules per kilogram per degree Celsius (J/kg·°C). For example, water has a high specific heat capacity of about 4184 J/kg·°C, meaning it takes 4184 joules of energy to raise the temperature of 1 kilogram of water by 1 degree Celsius. This is why water heats up and cools down more slowly compared to many other substances, like sand, which has a much lower specific heat capacity. The property of high specific heat is important for regulating temperature stability in environments and organisms. For instance, it enables large bodies of water to moderate climate by absorbing and releasing heat slowly, and helps living organisms maintain stable internal temperatures despite fluctuations in external temperature. In summary, a high specific heat means a substance can store and absorb a lot of heat energy with only a small change in temperature, providing thermal stability and resistance to rapid temperature changes.