The Ankh is a hieroglyph used in the Egyptian writing system as a trilateral sign, and is a stylised depiction of a sandal strap. It it shaped like a crucifix style cross with a loop instead of a top bar.
The sign has great religious significance in Egyptian religion, for the sign was commonly used as shorthand for "life", and was often used to represent the concept of giving life of breath in religious art. Gods are routinely shown carrying the sign in one hand, as if an object, whilst it is often held by a god under the beneficiaries nose, giving them the breath of life.
Following the enforcement of Christianity in Egypt (391AD), the Ankh sign was incorporated into Coptic iconography, where it remains today.
In modern times the Ankh has been widely adopted by a variety of groups. It is widely worn as a necklace, or occasionally bracelet as a protective amulet or charm, usually made of silver. The Ankh is also used as a symbol by some bands. Along with the Udjat, it is one of the most widely recognised symbols of Egyptian culture.