One of these is solar radiation, which is in the form of photons from the sun. The other is chemical bonds which are generally produced by organisms from their own source of energy. In the case of plants, photons are the source of energy, but in animals their food is solely from chemical bonds. Plants convert photons to chemical bonds. They then use the chemical bonds for the processes of life.
Animals use chemical bonds for the processes of life.
They obtain these chemical bonds from the organisms they eat, which may be plants or other animals. Laws of Thermodynamics Organisms are just like everything else in the physical world, they must obey the physical laws. For example, animals are subject to the laws of gravity just like a rock is. Obviously, when a bird falls out of a tree it doesn't fall like a rock, but gravity is still working on it. It overcomes the pull of gravity by expending energy.