Can someone explain to me the "hard problem of consciousness"?

This sort of discussion really just upsets people (not because of fighting, but because of how it makes people confused about themselves and others) for no real benefit.

The Hard Problem is solved, in the sense that it is known to be hard, and troubling. Let it be. There are so many more rewarding things to put the same effort to.

What would happen if we encountered very advanced beings from another world ? How would we determine whether they were robots or really living/conscious. They would talk, they might say they are alive.

They may have metallic bodies, is there anything to say that conscious beings cannot.

Disappointed not to see 'if I could explain it, it wouldn't be hard.'