For a glass of water, the number of molecules is astronomical. The ice chips probable look more disorder when we compare to the glass of water which looks uniform. However, according to thermodynamics the ice chips place limits on the number of ways the molecules can be arranged. The water molecules in the glass can be arranged in many more ways; as a result, they have grater multiplicity and therefore greater entropy.
The most general is to measure our ignorance about a system. The equilibrium state of a system, maximizes the entropy because, we have lost all information about the initial conditions, as a result, the entropy maximizing immediately maximises and our ignorance about the details of the system.
The probability of finding a system in a given state depends upon the multiplicity of that state. As a result it is proportional to the number of ways someone can produce that state. Here, it is a pair of dices, and in throwing this pair, that measurable property is the sum of the number of dots which are facing on the top. The multiplicity for two dots showing is just one because there is only one case of the pair that will give that state. For example, the multiplicity for seven dots is six, because there is six cases of the pair that will show a total of seven dots.