In computing, a client is a human being who utilizes a PC or else Internet service. A consumer can have a user account that recognizes the client by a username (also user name), screenname (also screen name), or else "handle", which is being resultant from the identical Citizen's Band radio term. To log in to an account, a client is usually compulsory to confirm himself with a password or else additional identification for the purposes of accounting, security, logging, as well as resource management.

Users are also extensively distinguished as the class of citizens that make use of a system without entire technical expertise necessary to completely understand the system. In most hacker-related contexts, they are also divided into lusers as well as power users. Both are terms of appropriation, but the latter connotes a "know-it-all" position.