What are [coherence](http://en.wikipedia.org/wiki/Coherence_%28physics%29) and [quantum entanglement](http://en.wikipedia.org/wiki/Quantum_entanglement)? Does it mean that two particles are the same? 

I read this in a book called [*Physics of the Impossible*](http://www.goodreads.com/book/show/1168341) by [Michio Kaku](http://en.wikipedia.org/wiki/Michio_Kaku). He says that two particles behave in the same way even if they are separated. He also says that this is helpful in [teleportation](http://en.wikipedia.org/wiki/Quantum_teleportation). How can this be possible? Could somebody please explain?