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.

A number of guidelines or [[rubric]]s govern which icons are on which parts of the iconostasis, although there is some room for variation. There are also guidelines for who should enter or leave the altar by which door. These guidelines were developed over the course of many centuries, with both theologically symbolic and practical reasons for them.

#North door (the north and south doors are often called "deacon's doors"). This will usually depict a deacon, usually St. Stephen the Protomartyr, or an archangel, usually St. Michael.

#South door. The same as above, though if a [[deacon]] is depicted, it is usually St. Philip or St. Lawrence, and if an [[archangel]], usually St. Gabriel.

#This is usually the icon of the Mystical Supper, the last supper our Lord ate with his friends and wherein he instituted the Eucharist.