Leptons are fundamental particles that do not interact via the strong nuclear force. Notable examples of leptons include electrons and neutrinos.

Leptons represent one of the two primary categories of fundamental particles, the other category being quarks. Importantly, leptons are not composed of smaller constituent particles, and their lack of interaction with the strong nuclear force means they do not engage with other particles through this particular force. Leptons are classified into three generations, each consisting of a charged lepton paired with a corresponding neutrino. The first generation comprises the electron and the electron neutrino, the second generation consists of the muon and the muon neutrino, and the third generation includes the tau and the tau neutrino.

The electron, the most recognized lepton, is found in atoms where it orbits the nucleus. The electron carries a negative charge and has a mass of approximately $9.11 \times 10^{-31}$ kg. In contrast, the electron neutrino is a neutral particle generated during specific types of radioactive decay and within the sun. It possesses an extremely small mass and interacts only weakly with matter.

Additional examples of leptons include the muon and the tau, which are heavier counterparts of the electron, along with their associated neutrinos. Leptons play a crucial role in particle physics, particularly in the study of the weak force, one of the four fundamental forces of nature. Furthermore, they are significant in astrophysics, where neutrinos are utilized to investigate the properties of the sun and other celestial bodies.