Teams are where all your Projects are added. For most, one Team might be enough where a single cost centre handles all billing.
For example, if you are in an engineering or architectural office in Melbourne, you might want to call your team 'Team Melbourne', with all projects associated with 'Team Melbourne' being handled by a single accounts team.
To delete a Team, navigate back to the Teams page and navigate to the Members area. Then select the Team member you would like to delete, select the ellipsis and then click 'Remove Member' and the 'Remove'.