鎖具(ju)(ju)(ju)是指(zhi)(zhi)起封閉作(zuo)用(yong)(yong)(yong)(yong)的(de)(de)器具(ju)(ju)(ju)，它包括鎖、鑰匙(chi)及其附件(jian)，一般解釋為(wei)“必須(xu)用(yong)(yong)(yong)(yong)鑰匙(chi)方能(neng)開(kai)(kai)脫的(de)(de)封緘器”，現在(zai)，鎖具(ju)(ju)(ju)除(chu)用(yong)(yong)(yong)(yong)鑰匙(chi)開(kai)(kai)啟外，還可以用(yong)(yong)(yong)(yong)光、電、磁(ci)、聲(sheng)及指(zhi)(zhi)紋等指(zhi)(zhi)令開(kai)(kai)啟。鎖具(ju)(ju)(ju)不(bu)單是防護用(yong)(yong)(yong)(yong)品(pin)，還具(ju)(ju)(ju)有“管理”和“裝飾(shi)”的(de)(de)作(zuo)用(yong)(yong)(yong)(yong)。在(zai)國際交往中也有一種(zhong)禮儀，用(yong)(yong)(yong)(yong)贈送(song)象征性的(de)(de)“鑰匙(chi)”作(zuo)為(wei)友(you)誼(yi)的(de)(de)表(biao)示(shi)。