Professor Susskind introduces statistical mechanics as one of the most universal subjects in modern physics in terms of it's ability to explain and predict natural phenomena. He begins with a brief introduction to probability theory and then moves on to draw the connection between the concept of laws of motion as rules for updating states of a system, and the probability of being in a given state. Proper laws of physics are reversible and therefore preserve the distinctions between states - i.e. information. In this sense, the conservation of information is more fundamental that other physical quantities such as temperature or energy.