What is the difference between vascular and avascular necrosis of the hip

is there a difference between vascular and avascular necrosis of the hip?

avascular necrosis is actually a name for a condition where there is blood loss or lack of blood in the bone causing cells and tissue to die prematurely.
necrosis is a term used to say theres premature death of cells and living tissue and vascular is a word for "related to the blood vessels" so I assume vascular necrosis is a why to say cells are dieing do to some problem related to the blood but not necessarily do to the lack of blood.