Conservative systems are commonly used in statistical mechanics, an area of physics that uses a particular mathematical framework to describe physical systems of an ideal gas.  In statistical mechanics models, the systems being studied are assumed to have a particular property, what Physicist Leonard Suskind called the conservation of distinction. This means that if one knows the current state of the system, then one knows the future state of the system. Signifcantly, one also knows the prior state of the system. Thus the system has memory and is deterministic going forward.