What is the purpose of the "Send Welcome Email" option under Advance in the user profile?

Sending welcome email from User profile

The "Send Welcome Email" option sends an email to the user with a link to set up their password and voicemail PIN. The email contains an authentication code. After entering the new password and voicemail PIN, the user is logged into the portal and directed to their new Home Page. If the email address and extension pass validation, the user receives a notification in the portal and a welcome email.

Below is what the Welcome email looks like: