User identification is a character group that uniquely identifies a particular user to an operating system of a computer for purpose of determining access rights and resource entitlement and for accounting.

• 用户标识符是一种字符组，它用来向计算机操作系统唯一地标识出某个特定用户，目的是决定该用户的数据访问(存取)权以及资源享有权，并为其记账。