The Fermi-Dirac distribution describes the statistical 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. The distribution is crucial for understanding the behavior of electrons in metals and semiconductors, as it helps predict how these particles fill available energy states at different temperatures. At absolute zero, all energy states below a certain level are filled, while those above are empty. As temperature increases, some particles gain energy and can occupy higher states, leading to a gradual filling of these states. The Fermi-Dirac distribution is essential in fields like quantum mechanics and solid-state physics, influencing the design of electronic devices.