An isochoric process is a thermodynamic process in which the volume of a system remains constant. This means that no matter how much heat is added or removed, the space occupied by the gas or liquid does not change. Because the volume is fixed, any heat transfer will result in a change in pressure and temperature, but not in volume. In an isochoric process, the relationship between pressure and temperature can be described by Charles's Law. For example, if you heat a sealed container of gas, the pressure inside will increase as the temperature rises, demonstrating how energy affects the state of matter while keeping the volume unchanged.