A phylactery is a container.
A lich phylactery contains a lich's soul. As long as a Lich's phylactery remains intact and undamaged, the lich will eventually regenerate its body and return to life.
Phylactery of Faithfulness
The Phylactery of Faithfulness is a small box containing religious scripture affixed to a leather cord and tied around the forehead. Commonly used by night elves and members of the Silver Hand, use of this item has started to spread through the Horde faithful. The wearer is aware of any action that would adversely affect their alignment and their standing with their own faith, including magical effects. This helps them solve ethical problems, allowing them to gain information prior to taking the action or associating themselves with the item if they take a moment to contemplate the act. ( )