System and Surroundings

In thermodynamics, a "system" refers to the specific part of the universe being studied, which can be anything from a chemical reaction, a machine, or a container of gas. The "surroundings" are everything outside the system that can exchange energy or matter with it. For example, if you have a hot cup of coffee (system), the air, table, and room around it make up the surroundings. These concepts help us analyze how energy flows, such as heat or work, between the system and its environment during processes.