An isochoric process is a thermodynamic process in which the volume of a system remains constant. During this process, any heat added or removed from the system results in a change in pressure and temperature, but the volume does not change. This is often observed in rigid containers where the gas cannot expand or compress. In an isochoric process, the first law of thermodynamics applies, stating that the change in internal energy of the system equals the heat added to it. This type of process is important in understanding the behavior of gases and is commonly studied in physics and engineering.