Quantum entanglement is a fundamental phenomenon in quantum mechanics that describes non-separable correlations between the quantum states of two or more particles. As a core academic concept and research area in quantum physics and information science, it investigates systems where the quantum state of each constituent particle cannot be described independently of the others, regardless of spatial separation. This characteristic non-local correlation is of significant theoretical interest and is recognized as a crucial resource for emerging quantum technologies such as quantum computation, communication, and sensing.