Desire is a something that you really want, that would align your values and who you are, having belief and self-love; something that you want doesn’t matter what others tell you. It’s living a life with purpose.
Greed, one the other part, comes from a place of lack to me: lack of self-esteem, self-love, and gratitude; or fear of being not enough. It is when you think of something you will be happy. And you will be happy for several minutes, a day, a week, maybe a month. But it will not last. It is when you want something because the world told you so and you look with envy at others. It’s when you want to impress others, or you want to prove yourself that you can do something.