The Deacon's Doors, also called the North and South Doors, are the two side doors of the iconostasis in an Orthodox church, placed toward the ends of the iconostasis on either side of the central Holy Doors. These doors are used frequently by deacons in entering and leaving the altar.
The South Door is typically the liturgical entrance to the altar, interpreted mystically as heaven. An icon of the Archangel Gabriel is generally depicted on the door because he is the "Messenger", whose announcement to the Theotokos marks the beginning of the Incarnation, our entrance to the heavenly realm. The North Door is the liturgical "exit" door, on which Archangel Michael is depicted because he is the "Defender" of God and guards the door to heaven..
Sometimes icons of sainted deacons are depicted on these doors instead of the archangels. In such cases an icon of either Ss. Philip, Lawrence, or Ephrem the Syrian may be on the South Door and St. Stephen the Protomartyr on the North Door.