After a quote from Picard is , The economics of the future is somewhat different. You see, money doesn’t exist in the 24th century. The acquisition of wealth is no longer the driving force in our lives. We workto better ourselves and the rest of humanity, is no money in the Star Trek Universe.
But what about the Ferengi´s? They have the platinum as currency . How that works out ? Are there more in Star Trek universe who uses a kind of currency?