Let's talk about bodies, such as a bicycle or a rock fireplace. One of the properties of a body is the material it is made of. The question "What is it made of?" is often asked is difficult to answer because many different materials are used - for example, in the case of a bicycle.
Specific heat is a property of a material, like density or colour. While density predicts the mass of a body of any given volume made of a given material, and colour allows us to guess how well a body made of that material absorbs light, specific heat tells us how much heat has to be added to a body to raise the temperature of a body made of that material by a certain number of degrees.
Thus, the specific heat of a substance is important when, for example, we are designing a heat bag or want to heat a house in winter with the heat stored in summer.
Specific heats of some substances
How is this knowledge useful to us?
If we know the specific heat of a material, we can estimate how much heat we can put into the body from that material. In addition, we can tell how quickly that body will heat up and cool down. This is very useful knowledge for choosing food, for example, or for detecting tumour cells in medicine.