Updated Oct 16, 2020 · 3 min read

What is a username?

A username (or user name, user ID, or account name) is a name that uniquely identifies a user in a system. Through usernames, multiple users can use the same system at the same time.

Sometimes, users are assigned a username, while other times, users can create their own usernames as long as they're unique and meet certain criteria, such as using a set of alphanumeric characters. Some systems use an email address as the username.

In username password authentication, a username is paired with a password to authenticate a user into a system. Once signed in, your username may appear on the screen and you can modify personal settings that are associated with your username.

Related Terms


Alphanumeric, also referred to as alphameric, refers to the set of alphabetical (letters) and numerical characters in a given language.


Authentication is the process of verifying the identity of a user. A common form of authentication is username password authentication...


A password is a series of characters that enable a user to sign in to a system, such as a file system, application, or program.