Quantum optics delves into the quantum characteristics of light fields and their interactions with matter. It unveils that light doesn't merely display wave-like properties; rather, it is also made up of discrete photons. By exploring quantum states of light, including coherent states and squeezed states, as well as non-classical phenomena such as quantum entanglement, we can propel technological breakthroughs in areas like quantum communication, quantum computing, and ultra-precision measurement.