An '''iconostasis''' (also '''iconostas''' or '''icon screen''') is a screen or wall which serves as a stable support for [[icon]]s and marks the boundary between the [[nave]] and the [[altar]] or sanctuary. The term can also refer to a folding, portable set of icons. There has been historically and continues to be a vast range of styles for iconostases: Some are simply two icons of the [[Theotokos]] and the [[Jesus Christ|Lord]]; the most complex, cathedral icon screens have multiple tiers with many icons per tier. The iconostasis is perhaps the most distintive feature of [[Byzantine Rite]] churches. It evolved from the Byzantine templon, originally a small rail without icons that marked the boundary between the nave and the altar.