Endings, not predictions
Dreaming of death — your own or someone else's — most often symbolizes the end of a phase, a role, a relationship dynamic, or a version of yourself. It tends to appear at thresholds: leaving a job, a move, a breakup, a milestone birthday. The dream is the psyche marking that something is concluding so something else can begin.
Whose death, and what they represent
Dreaming of a living person's death usually says more about a changing relationship or a quality you associate with them than about them literally. Dreaming of your own death frequently accompanies major personal transformation — the 'old self' giving way. The identity of the figure is a clue to which part of your life is turning over.
When grief is the real subject
After a real loss, death dreams can be part of how the mind processes grief, and they may bring the person vividly back. These are worth treating gently — less a symbol to decode than an experience to sit with, and sometimes to talk through with someone you trust.