A user is an agent, either a human agent (end-user) or software agent, who uses a computer or network service. A user often has a user account and is identified by a username (also user name). Other terms for username include login name, screen name (also screenname), nickname (also nick), or handle
Users are also widely characterized as the class of people that use a system without complete technical expertise required to understand the system fully. In hacker-related contexts, such users are also divided into lusers and power users.
It includes -