鎖(suo)具(ju)(ju)是指(zhi)起封閉作(zuo)用(yong)(yong)(yong)的器(qi)具(ju)(ju)，它包括鎖(suo)、鑰(yao)(yao)匙(chi)及其附(fu)件，一般解(jie)釋為“必(bi)須用(yong)(yong)(yong)鑰(yao)(yao)匙(chi)方能開(kai)脫的封緘器(qi)”，現(xian)在，鎖(suo)具(ju)(ju)除(chu)用(yong)(yong)(yong)鑰(yao)(yao)匙(chi)開(kai)啟外，還可以用(yong)(yong)(yong)光、電、磁、聲及指(zhi)紋等指(zhi)令開(kai)啟。鎖(suo)具(ju)(ju)不單(dan)是防(fang)護用(yong)(yong)(yong)品，還具(ju)(ju)有“管理”和“裝飾”的作(zuo)用(yong)(yong)(yong)。在國際交(jiao)往(wang)中也有一種禮儀，用(yong)(yong)(yong)贈送象征性的“鑰(yao)(yao)匙(chi)”作(zuo)為友誼的表示。