Statistical physics is a fundamental branch of physics that connects microscopic particle behavior with macroscopic observable properties. It uses statistical methods to describe systems containing a large number of particles, where deterministic approaches are impractical. Starting from basic concepts like random walks, microstates, and macro­states, it builds toward powerful tools such as Gibbs ensembles and the ergodic hypothesis. Through microcanonical, canonical, and grand-canonical ensembles, it explains thermodynamic equilibrium, entropy, and fluctuations. This framework provides deep insights into gases, magnetism, and the time evolution of physical systems.