The confirmation request will be an email message telling the person that they have requested to join this mailing list, and the person will have to respond to the confirmation message in order to become a full member. The new member's status will be set to confirm until the confirmation response is received, and the person will not receive mail from the mailing list until the confirmation is received.
Confirmation serves several purposes.
It is quite common for people to mistype their email address when subscribing to a mailing list using the Lyris Web Interface. Without confirmation, the Lyris Server would waste effort trying to send mail to this incorrect address. Another need for confirmation is to counter a common form of Electronic Terrorism. If that person's email server is not perfectly configured, the act may crash the person's email server, use vast qualities of Internet bandwidth, or prohibit other people sharing the email server from receiving their email. The Confirmation feature blocks this form of Electronic Terrorism.