数据的一种集合，其中每一项可唯一地被一个标号或相对于其它项的位置或某些其它方法所标识。 A collection of data in which each item is uniquely identified by a label, by its position relative to the other items or by some other means.
一个别名或替换标号，可用来指程序中的某一数据元素或某一位置。 An alternate name or label used to refer to the same element or a point in a program.
