CPT symmetry is a fundamental principle in physics that combines three transformations: C for charge conjugation, which swaps particles with their antiparticles; P for parity transformation, which flips spatial coordinates; and T for time reversal, which reverses the direction of time. Together, these transformations suggest that the laws of physics should remain unchanged when all three are applied simultaneously. This symmetry is crucial in understanding the behavior of subatomic particles and the interactions described by quantum field theory. It implies that if a process occurs in one way, the combined effects of CPT transformations should allow it to occur in a corresponding way, maintaining consistency in physical laws across different scenarios.