When your character on World of Warcraft dies, you are teleported to the nearest graveyard and become a ghost. The world goes blue and ghastly and you are unable to cast spells. All of your buffs and debuffs are removed and your equipped items become slightly more broken.
Your ghostly spirit has left your body behind, and to resurrect you can either find your body, be resurrected by another player, or speak the spirit healer at the graveyard.
The effects of being a ghost are pretty interesting. Exploring a region when in ghost form can be easier than doing so as a live character – a ghost cannot die, with the exception of fatigue. There are no mobs, fall damage, or other players to worry about!
The special effect of ghost form is one of my favourite parts of the World of Warcraft. Seeing everything go dim and ghoulish for the first time was a complete shock!