Deathly Hallows are featured in the seventh installment of the Harry Potter book series by JK Rowling. They are a trio of objects fabled to have been made by Death. Anyone who possess all three hallows is supposed to become the "Master of Death."
The Hallows are:
The Elder Wand: The most powerful wand in the world, nearly unbeatable. The Elder Wand will only be truly powerful if its current owner took it themselves, by force, from the previous owner. Contrary to popular belief, you do not have to kill the previous owner to win the wand's allegiance.
The Invisibility Cloak: This hallow has been duplicated and many cloaks now exist, but this one is special. It renders the wearer completely invisible. It is not hampered by spells and will never wear out over time. It also offers protection, which no other invisibility cloaks do.
The Resurrection Stone: A stone that will call the dead back into the world of the living. But they will not be truly like they were, they still belong to the world from which they came. Most who call them back are unsatisfied.
The symbol of the Deathly Hallows is a circle (symbolizing the stone), sliced down the middle with a line (symbolizing the wand), and surrounded by a triangle (symbolizing the cloak).
Harry Potter is the only one who is able to unite the hallows because he is the only one worthy. But he drops the stone, and puts away the wand, never to use them again.
"Harry Potter managed to unite all three Deathly Hallows! Now he is the Master of Death."
"I think the most useful of the Deathly Hallows is the Elder Wand."