As heat energy reaches an object it can be absorbed in a similar manner to the way sponges absorb water. Heat enters an object, warming it. The longer the object is exposed to the heat source, the more heat it absorbs.
A good example of heat absorption is the traditional Christmas turkey. When first put into the oven, the turkey is cool and raw. Slowly as heat is absorbed by the turkey, it becomes hotter and hotter until the entire bird is cooked, juicy, and ready to eat.
Different objects absorb heat at different rates. Some objects are excellent absorbers, while others are very poor absorbers. Generally, dark colored objects absorb better than do lighter colors objects.
Think about that for a moment. Why do you suppose this is the case? Why do dark colors absorb better than light colors? Why do dark colors look dark in the first place? Dark colors look dark because they absorb more light, making them harder to see.