“Quantum entanglement is a physical phenomenon that occurs when a pair or group of particles are generated, interact, or share spatial proximity in a way such that the quantum state of each particle of the pair or group cannot be described independently of the state of the others, including when the particles are separated by a large distance.”
One more explanation,
Source:
[1] Wikipedia Contributors. “Quantum Entanglement.” Wikipedia, Wikimedia Foundation, 19 Nov. 2020, en.wikipedia.org/wiki/Quantum_entanglement. Accessed 24 Nov. 2020.