Ghost

A Ghost is a piece of equipment issued to each Guardian.

Overview
Appearing as a small, floating drone, Ghosts were created by the Traveler "with its dying breath", and have spent their time since the Collapse searching for their guardians. While Ghosts can revive their Guardian from death, Ghosts themselves are irreplaceable. The Ghost serves as a scout, librarian and mechanic, waking ancient machinery and cracking ancient codes. They seem to possess some degree of artificial intelligence, being able to converse with their masters in a very human manner.

Ghosts can support Guardians by performing certain actions such as illuminating darkened areas, repairing technology from the Golden Age, informing Guardians of incoming hostile threats, and providing communications.

Gameplay
Ghosts inform players of new objectives, and serve as a marker beacon/respawn point when a player's character dies during cooperative play. Ghosts notify players when a Guardian has left the area or revived. A Ghost can revive a player by holding the X button on the Xbox 360/Xbox 1, or the square button on the Playstation 3/4. This can only be done in close proximity to a fallen player.

On occasion, Ghosts can scan certain objects and provide additional context to the Guardian. For example, scanning a dead Cabal on Phobos will have Ghost describe what legion it's from.

Ghost Shells
Ghost shells change the appearance of your ghost. The Taken King adds defensive boosts and additional effects to ghost shells. Rare shells have a single perk, while legendary shells have several to choose from. Shells can be purchased from The Speaker or Lord Shaxx.

Trivia

 * It is possible to change the way a player's Ghost looks with Ghost Shells.
 * The Ghosts are sometimes called "Dinklebots" by players, as a nod to Peter Dinklage, who provides their voice in the game. As of The Taken King, Nolan North will be replacing Dinklage, including redubbing lines from the original Destiny game.
 * It was indicated pre-release that players need certain equipment before having access to a Ghost. This is currently not the case, as the Ghost is present with the player from the start of the game in current builds (having revived them).
 * Holding out a Ghost in some sections of the Moon opens doors. However, they are pitch black inside.
 * Ghosts may be deactivated and revived.
 * The Ghost's saying "We always visit such cheerful places" is a possible reference to Cortana's line in Halo 2 on the level Delta Halo, saying: "We always visit such nice places".
 * Dead Ghosts can be found in the game world which, upon revival, unlock new Grimoire cards.
 * According to an advertisment for Destiny, Ghosts existed during the Golden Age. This is likely an error as all other sources have stated that Ghosts were created by the Traveler after the Golden Age.
 * The Ghost was depicted as taking part in the Ice Bucket Challenge in a short video by Bungie, which donated to the campaign.

List of appearances

 * Destiny