The word "序列号" is formed by combining three characters: 序, meaning "order" or "sequence"; 列, meaning "row" or "list"; and 号, meaning "number" or "identifier". The characters 序 and 列 together create the compound term 序列, which means "sequence" or "series", and then 号 is appended to specify that it is a number associated with that sequence, resulting in the meaning "serial number" or "sequence number".