A Contact Group, known in previous Outlook versions as a distribution list, is a grouping of email addresses collected under one name.
A message sent to a Contact Group goes to all recipients that are listed in the group.
You can include Contact Groups in messages, task requests, meeting requests, and in other Contact Groups.
In the following video we show how to manage your groups:
In the following video we show how to send email to a group using the bcc field: