The word 人民币 is formed by combining the characters 人 (person), 民 (people), and 币 (currency). 人民 together means "the people", and adding 币 specifies "currency of the people", directly creating the term for China's official currency.
Word Definition - 人民币
rén mín bìRenminbi (RMB), PRC currency; The unit is RMB Yuan 人民币元 or simply 元.