Fermi-Dirac statistics is a statistical method used to describe the distribution of particles, specifically fermions, which are particles that follow the Pauli exclusion principle. This principle states that no two identical fermions can occupy the same quantum state simultaneously. As a result, the occupancy of energy levels by fermions is determined by their energy and temperature, leading to unique distributions at different conditions. This statistical approach is essential in understanding the behavior of systems like electrons in metals and nuclei in atomic physics. It helps explain phenomena such as electrical conductivity and the properties of degenerate matter found in neutron stars.