How did the use of standard currency or coins help the economy of the Roman Empire?

Augustus created a new standard currency. There was already a standard currency previously, during the Republic. A standard currency was needed to have a uniform monetary system for payments and for the exchange of goods throughout the empire. Augustus followed an innovation introduced by Julius Caesar. Caesar was the first ruler who introduced coins baring his own portrait. Augustus introduced coins with his own portrait, establishing the tradition of linking the emperor's sovereignty with the issuing of coinage. Subsequent emperors also issued coins with their image. Augustus also reformed the coinage system to rationalise it and make it more fitting with the new economic conditions of the empire.