Quantum effects refer to phenomena that occur at the quantum scale, where the laws of classical physics no longer apply and quantum mechanics governs the behavior of particles and energy. These effects include superposition, where particles can exist in multiple states simultaneously, and entanglement, where particles become correlated despite being separated by vast distances. Quantum effects have profound implications for a wide range of scientific fields, including quantum computing, quantum cryptography, and quantum information theory. They are also being increasingly explored for their potential applications in technology, communication, and beyond.