CORSIKA is a detailed Monte Carlo program designed to simulate extensive air showers (EAS) initiated by high-energy cosmic ray particles, including protons, light nuclei up to iron, photons, and other particles. The program tracks particles through the atmosphere until they interact with air nuclei or decay. Hadronic interactions at high energies are described using five reaction models: VENUS, QGSJET, DPMJET, SIBYLL, and HDPM. At lower energies, GHEISHA or ISOBAR models are used. Particle decays are simulated up to the 1% level, and electromagnetic processes can be handled using EGS4 or NKG formulas. Options for Cherenkov radiation and neutrino generation are also available. The program is widely used in various experiments, from Cherenkov telescopes to high-energy cosmic ray studies, and is continuously updated to improve accuracy and functionality.CORSIKA is a detailed Monte Carlo program designed to simulate extensive air showers (EAS) initiated by high-energy cosmic ray particles, including protons, light nuclei up to iron, photons, and other particles. The program tracks particles through the atmosphere until they interact with air nuclei or decay. Hadronic interactions at high energies are described using five reaction models: VENUS, QGSJET, DPMJET, SIBYLL, and HDPM. At lower energies, GHEISHA or ISOBAR models are used. Particle decays are simulated up to the 1% level, and electromagnetic processes can be handled using EGS4 or NKG formulas. Options for Cherenkov radiation and neutrino generation are also available. The program is widely used in various experiments, from Cherenkov telescopes to high-energy cosmic ray studies, and is continuously updated to improve accuracy and functionality.