This lecture explores CP violation in the early universe, the weak interaction of quarks, the GIM mechanism, the CKM matrix, Feynman rules, and the neutral kaon system. It delves into strangeness oscillations, CP eigenstates, decays of CP eigenstates, and the CPLEAR experiment. The lecture also covers CP violation in semileptonic decays, CP violation and the CKM matrix, and the summary of the CKM matrix and CP violation in particle physics.