鎖(suo)具(ju)是指(zhi)起封閉作(zuo)(zuo)用(yong)(yong)(yong)的器(qi)具(ju)，它(ta)包括鎖(suo)、鑰(yao)(yao)匙及其附件，一(yi)般解釋為“必須用(yong)(yong)(yong)鑰(yao)(yao)匙方能開(kai)(kai)脫的封緘器(qi)”，現在(zai)，鎖(suo)具(ju)除用(yong)(yong)(yong)鑰(yao)(yao)匙開(kai)(kai)啟(qi)外，還可(ke)以用(yong)(yong)(yong)光、電、磁、聲及指(zhi)紋等(deng)指(zhi)令開(kai)(kai)啟(qi)。鎖(suo)具(ju)不單是防護用(yong)(yong)(yong)品，還具(ju)有“管(guan)理”和(he)“裝飾”的作(zuo)(zuo)用(yong)(yong)(yong)。在(zai)國際交往中(zhong)也有一(yi)種禮儀，用(yong)(yong)(yong)贈(zeng)送(song)象征性的“鑰(yao)(yao)匙”作(zuo)(zuo)為友誼的表示。