Fourier' heat flow equation that explains the relation between quantity of heat flow and the temperature difference, Ohm's law which describes the steady flow of electric charge in a wire, Poiseuille's equation governing fluid flow being proportional to the pressure difference are all analogies of the generalized steady flow of different entities namely heat, charge and fluid.
You can see that the volume of liquid has a correspondence with the amount of electric charge and the quantity of heat and that the pressure difference causing the flow of liquid is like the potential difference causing an electric current and the temperature difference causing a flow of heat.