Prosperity refers to the state of wealth, abundance and success.
This term is mostly used to talk about a country that is rich and peaceful (see peace), where people want for nothing more. We also use it for a company whose business works perfectly.
However, prosperity can also concern one single individual. We say that someone is prosperous when it seems like everything is great in their life : they’re healthy, they’re happy in their professional and personal life, they’re wealthy... (see longevity).
Everyone may have a different view on prosperity because success is not the same for everyone. An achievement can be small for one person and be a huge success for another.