Some organizations use My Teams under My Account on their Dashboard to form separate groups under their organization to manage particular functions (e.g. Greeters or Ushers for a Church, or Kitchen or Warehouse for a Charity). Using Teams allows leaders of those groups to communicate needs that relate to those functions only to certain individuals (those who are assigned to those teams). Individuals on those teams will receive automated email notifications when new needs are posted by the Team leader.
Administrators of the overall organization may assign those registered under their organization to groups/teams on the Approved Members page under My Account on their Dashboard by checking the box to the left of those names, clicking the Assign __ Members to Teams button, selecting the team from the drop down list, and then clicking Assign.