When we talk about entropy, we say it comes from our inability to completely describe the state of a system. Also, we say it is a property of the system (like entalphy). That's confusing me a lot. If entropy is a property, how can it come from our inability to describe the system? Or it's just a construct? Something that we use to describe reality? Let's say we had some entity (like the Laplace Demon) that could completely describe the state of a system (knowing exactly the position and velocity of all the particles within it), so there would be no entropy? I just need some clarification about this.