An isolated system is a physical system that does not interact with its surroundings. This means that no energy, matter, or information can be exchanged between the system and its environment. In other words, the total energy and mass within the isolated system remain constant over time.
Isolated systems are often used in scientific experiments and theoretical analysis to simplify the study of specific phenomena without external interference. Examples of isolated systems include a sealed container with no exchange of matter or a closed system where no energy transfer occurs with the surroundings.