 Here's a water wave. It's described by a wave function that determines its operation and a wave equation that determines the change in the function over time. We can channel this wave into two directions, say A and B. With enough time, we can create a great distance between the two branches. If we examine branch A at some time t and find that the wave is at a peak, we will know immediately that at that exact time the branch B wave will also be at a peak. We don't ask how did the A branch inform the B branch that it needed to be at a peak. We did not analyze whether information was flowing from A to B faster than the speed of light. We simply note that both branches are a part of a single wave equation that determines its state at any time t. Of course, if we drop channel A's water off a cliff, the wave in channel B will continue on its merry way. To help isolate the key differences between classical mechanics and quantum mechanics, let's look at one more classical example. Here we start with two coins, each with the heads on one side and the tails on the other. If we put them both into a spin and send them up the two channels, we note that during the journey they exhibit neither heads nor tails. But they carry a probability that, once stopped, they will either come up heads or tails. The probability is 50-50. But unlike the water wave, the results for one of them does not tell us anything about the results of the other. They are independent. But like water waves, the outcomes can be predicted if the starting conditions and channel environment are known. For the quantum mechanics view, we'll start out with two electrons that have been put together to entangle them. Entangled particles are particles that have their quantum states described by a single wave function. The quantum state in question here is the electron's spin. In their lowest energy state, when one is up, the other will be down. Now we send one of the electrons down channel A and the other down channel B. As they travel, they will not exhibit any spin much like the coins did not exhibit heads or tails. In this example, the moment the electron and channel A interacts with a strong magnetic field, it will bring either up spin or down spin to the interaction. At the same instant, the other electron's spin is determined. If A was up, B will be down. If A was down, B will be up. This is as expected because both particles are following the one wave function. It does not matter how far apart the two particles are.