The term is "Hallows," and there were three of them. See the story "The Three Brothers" in The Tales of Beedle the Bard which JK Rowling has written and been published. In brief, they were:
The Elder Wand - belonged to Antioch Peverell, the eldest of the three brothers. Over time, the wand passed violently from wizard to wizard until it ended up with Grindelwald, then Dumbledore, and eventually Voldemort - altough Voldy couldn't command the full power of the wand as he didn't gain its allegiance, become its master, because he never captured it.
The Resurrection Stone - belonged to Cadmus, the middle brother. It had the power to raise the dead, and ended up in the Slytherin family, and later the Gaunts (Voldemort's mother's family). Voldemort murdered his maternal grandfather to get the stone (and the ring it had been made into) and used the murder to create a Horcrux. This makes the Resurrection Stone the only object that's both a Horcrux and a Hallow. Voldemort never knew about the story of the Hallows or that the Stone ws one.
The Invisibility Cloak - belonged to Ignotus, the youngest Peverell brother, was passed through the generations and ended up with the Potter family. Harry is the current owner.