Final answer:
Thermodynamics is the study of thermal energy changes in systems, which can be open or closed in nature.
Step-by-step explanation:
The study of thermal energy changes that occur in a nearly isolated system is known as Thermodynamics. This field of physics involves understanding how energy is transferred within physical matter. Specifically, when considering the energy transfer that takes place when heating a substance, such as a pot of water on a stove, we observe multiple components (the stove, pot, and the water) interacting as a system. An important aspect of thermodynamics is distinguishing between open and closed systems. An open system can exchange energy with its surroundings, like the stovetop system that loses heat to the air. In contrast, a closed system cannot transfer energy to its surroundings.