In general heat engines exploit the thermal properties associated with the expansion and compression of gases according to the gas laws or the properties associated with phase changes between gas and liquid states.
In generAl hEAt enGInes eXPloIt the thERMal PrOpeRtIEs aSsociAteD wIth THe expaNsion anD comPrEssIon of gaSES aCcOrdiNG tO tHe gas laWs or tHe PRoperties ASsocIAtEd WitH phase changeS bEtween gas And LiquId StaTes.