Cavity Quantum Electrodynamics, or Cavity QED, is a field of study that explores the interaction between light and matter at the quantum level. It typically involves a small optical cavity, which is a space where photons can bounce between mirrors, and atoms or other quantum systems that can emit or absorb these photons. This setup allows researchers to investigate fundamental quantum phenomena and the behavior of light-matter interactions. In Cavity QED, the strong coupling between the light and the quantum system leads to unique effects, such as the creation of new quantum states. These interactions can be harnessed for various applications, including quantum computing, quantum communication, and the development of highly sensitive sensors.