Gas is the state of matter which has high kinetic energy and occupies the entire available space of container. The Gas molecules are at great distance from each other. So, their is negligible interactions between the gas particles. In order to bring the gas molecules closer to each other and to make interactions between them an external pressure is applied along with decreasing the temperature. In this way interactions are made between gas particles and they liquefy and solidify. This property by which the gas particles are brought together by applying pressure is called as COMPRESSIBILITY.