Dreaming of one's own death could indicate a significant change in the dreamer's life. This change is typically one of perspective or spiritual outlook.
Dreaming of the death of a loved one can indicate that the dreamer is lacking in some element that this person embodies. It could also suggest that whatever this person represents for the dreamer is completely absent from the dreamer's life.
A dream in which a person dreams of someone who is dead can mean that the dreamer is trying to resolve the loss of this person. It could mean that the dreamer is trying to resolve feelings or memories connected with the deceased. The dreamer could be going through a period where he or she is transitioning from relating to the dead person as a reality to relating to them as an inner memory.