Users can create accounts using their OpenID, assign one or more OpenIDs to an existing account, and log in using an OpenID. This lowers the barrier to registration, which is good for the site, and offers convenience and security to the users. OpenID is not a trust system, so email verification is still necessary. The benefit stems from the fact that users can have a single password that they can use on many websites. This means they can easily update their single password from a centralized location, rather than having to change dozens of passwords individually.