Each Clan has one Leader. When you create a Clan you automatically become the Leader, but you can assign leadership to another member at any time. The Leader can promote and demote Clan members, invite and kick members, and set the Clan message.
Officers can promote other members to Officers, demote other Officers, invite new members and kick members out of your Clan. Only assign Officer status to Clan members you trust. There is no limit on the amount of members who can be Officers.