鞭为一种由金属制的棒型打击武器，有像刀剑一样的握柄，打击部有节状且最前端有尖。在中国被归类为十八般兵器中的一种冷兵器。

中国的「鞭」分为两种，其一为策，用以驱马，驾车，其二为鞭，用以行刑，或当作武器使用。作为武器用的鞭有棱有节，与之相似的锏则无棱无节。

古代的鞭多指以坚硬金属制成的棍棒类武器，无刃，与长节软身的软鞭相对。鞭为短兵器，多以铁、铜、钢等物料铸造，以重量见称，是中国十八般兵器的其中一种，以单用为主，并配合其他武器（通常为长兵器）合用。亦有两手各执一根鞭的用法，用户须有较强的膂力，方可运用自如，如《水浒传》中呼延灼所使双鞭就是「左手的重十二斤，右手重十三斤」。

A whip is a tool traditionally used by humans to exert control over animals or other people, through pain compliance or fear of pain, although in some activities whips can be used without use of pain, such as an additional pressure aid in dressage. Whips are generally of two types, either a firm stick device designed to strike directly, or a flexible whip which must be swung in a specific manner to be effective, but has a longer reach. There are also whips which combine both a firm stick (the stock or handle) and a flexible line (the lash or thong), such as hunting whips.