There are 4 ranks in clans - Leader, Commander, Officer, Сommon Clanmate.

Leader can dissolve the clan, invite and approve requests from other players, delete clan members, promote to officers, change clan leader, start boss battles, start clan war and control clan treasury.

Commander can invite and approve requests from other players, delete clan members, promote to officers, start boss battles and start clan war.

Officers are people helping the Leader with Clan. They can invite and approve requests from other players.

Сommon Clanmate just a clan member.

Also there is mechanism that automatically change Clan Leader if he don't play game over 21 day and give Leadership to suitable Clanmate. In this case all involved players are received notification.