Statistical mechanicsexplains the simple behavior of macroscopic matters composed of a large numberof microscopic units; solving for the complex behavior of the latter ispractically impossible. Study of statistical mechanics provides useful conceptsand methods, including ensembles, phases, fluctuations, and correlations, to a plethoraof diverse disciplines in science and engineering. These ideas, originallyderived from physics and chemistry, has also infiltrited into biology,genetics, sociology, epidemiology, and finance. With this background in mind,this course will not focus on properties of specific matters; instead, topicsare chosen to reflect universal, emergent properties of a large group ofindependent or interacting units from a diverse set of physical systems. Inaddition to covering key statistical mechanics frameworks in equilibriumsystems, this course will also introduce general approaches for dealing withsystems out of equilibrium.