Can you explain to me what are the signs of narcissism in somebody?

Healthy & unhealthy: Important to remember that there is healthy narcissism and unhealthy narcissism. When it's healthy, the person has appropriate self-esteem and good feelings about herself. When it's unhealthy, the person is very self-involved and/or needs a lot of "stroking" and external reinforcement in order to feel ok about herself -- and, even then, the need goes so deep that it's almost insatiable.

Narcissism: The hallmark of a narcissist is an immense ego, grandiosity, and self-importance, as well as being entitled, and a tendency to use and objectify others as well as thinking of people in all-good or all-bad terms instead of shades of gray. The core of a narcissist is profound insecurity.