shares an article from ScienceAlert
Quantum communication is a strange beast, but one of the weirdest proposed forms of it is called counterfactual communication -- a type of quantum communication where no particles travel between two recipients. Theoretical physicists have long proposed that such a form of communication would be possible, but now, for the first time, researchers have been able to experimentally achieve it -- transferring a black and white bitmap image from one location to another without sending any physical particles... It works based on the fact that, in the quantum world, all light particles can be fully described by wave functions, rather than as particles. So by embedding messages in light the researchers were able to transmit this message without ever directly sending a particle.
It's different than quantum entanglement (which Einstein described as "spooky action at a distance.") The article describes it as "a pretty cool demonstration of just how bizarre and unexplored the quantum world is."