According to quantum mechanics, a pineapple can exist in multiple states at once. This is known as superposition.
Here is a graphical representation of a pineapple wave function:
Quantum entanglement is when two pineapples are connected in such a way that the state of one affects the state of the other.
Try this simple experiment to see entanglement in action:
And that's not all there is to quantum mechanics, but it's a good starting point.
Learn more.