Account

In computing, a user is a person who uses a computer or Internet service. A user may have a user account that identifies the user by a username (also user name), screen name (also screenname), or "handle", which is derived from the identical Citizen's Band radio term. To log in to an account, a user is typically required to authenticate himself with a password or other credentials for the purposes of accounting, security, logging, and resource management.

http://en.wikipedia.org/wiki/User_%28computing%29