A number system is determined by the number of characters available for representing numbers. The decimal system, for instance is based on the ten digits 0..9, the binary system is based on the digits 0 and 1, the hexadecimal system is based on 16 characters (0..9 and A..F).
一个数字系统是由表示数字的可用字符数量决定的。举例来说，十进制系统是以十个数字 (0..9) 为基础，二进制系统是以 0 和 1 两个数字为基础，十六进制系统是以 16 个字符 (0...9 和 A...F) 为基础。