A system which can exchange matter as well as energy with its surroundings is called open system.
The presence of reactants in an open beaker is an example of an open system. A system which can exchange only energy but not matter with its surrounding is called a closed system.
Pressure cooker is an example of closed system. A system which can exchange neither energy nor matter with its surrounding is called an isolated system. The presence of reactants in a thermos flask is an example of an isolated system.
