编号 (biān hào) has two parts of speech: as a verb, it means 'to number' (assign a sequential label); as a noun, it means 'serial number' or 'reference number' used for identification within a system. This differs from 号码 (hào mǎ), which is a number used for contact (phone number, room number), and from 数字 (shù zì, 'digit/figure') and 数目 (shù mù, 'amount').