What is entanglement? Entanglement is the quantum phenomenon where the properties of two particles are intertwined even if they are separated by great distances from each other. Picture this: You are looking for a set of gloves. If you found the right glove alone in your closet, you can be certain the missing glove would fit your left hand. The two gloves could be described as entangled, as knowing something about one would tell you something important about the other that isn't a random feature