Needs have a special meaning in the Spine Model, a meaning which we have appropriated from the NVC view of the world. They are common to all people and not tied to any particular circumstance or strategy for fulfilling them.
A Want is a combination of a Need and the strategy you have chosen to meet that Need. Often we are not conciously aware of that our Wants have these two distinct parts. We treat the Want as if it was a Need, and persist even when it is not meeting the underlying Need.
As an example, you may think of money as a basic need. It isn’t, it is a Want - a strategy for meeting deeper needs. By looking for answers to the question “Once you have enough money, what would you have?”, you can start to get to the underlying needs. Possibly they may include saftey, comfort or self expression.
By considering why you have the Want, what about it is important, you can start to explore the underlying need, and perhaps find different strategies that may be more appropropriate, or aligned to others.