Quantum entanglement is a phenomenon in quantum mechanics where two or more particles become correlated in such a way that the properties of one particle are linked to the properties of the other particle(s), even if they are separated by large distances.

When two particles become entangled, their quantum states become linked, meaning that the state of one particle cannot be described without also considering the state of the other particle. This can happen even if the particles are separated by vast distances, and any change to the state of one particle instantaneously affects the state of the other particle(s), regardless of the distance between them. This concept was famously described by Einstein as “spooky action at a distance.”

Quantum entanglement is a key feature of quantum mechanics and has been demonstrated experimentally in numerous contexts. It is also a subject of intense research interest due to its potential applications in fields such as quantum computing and cryptography.