A unique string of characters input by an authorized user in order to gain access to a system or to protected information in the system. Passwords are usually not displayed on terminal screen upon input, in order to preserve their secrecy.

• 被授权的用户为取得对系统或系统中被保护的信息的存取权而输入给系统的专门的字符串。为使口令字保密，输入时口令字一般不在终端屏幕上显示出来。