The name people use to identify themselves when logging into a computer system or online service. Spaces are generally not allowed in the username, and in most situations, both a username (user ID) and password are required.
In an Internet email address, the username is the part before the @ sign. For example, KARENB is the username in email@example.com
. AOL calls a username a "screen name."
A Username Can Be an Email Address
For some sites, a person's email address can be used instead of making up a name. Sometimes a username must be the email address (see below).
Username or Email Address?
These Google mail server settings ask for "User Name" when, in fact, an email address must be entered and not some made-up identity. Many websites create confusion like this and may even ask for "username" in one dialog and "email address" in the other.