What is entropy? I've watched countless youtube videos and still don't get it. I'm particularly interested in the engineering interpretation, with carnot cycles. This whole time I believed that entropy change has to do with change in the working fluid, such as increasing the fluid's temperature would increase it's entropy. But it never made sense how there would be absolutely no entropy change (in an idealized, reversible cycle) when the fluid passes through the turbine and loses temperature. It's the exchange of heat with the system that actually matters, and in an ideal case scenario, where the turbine doesn't exchange heat with the system, there is no entropy change.

Does anyone know of a good source where I learn to understand this?