In the narrower sense it refers to a devotional painted wooden panel.
The icon is the result of the synthesis of three different cultures: Greek, Roman and Christian.
The technique of Byzantine art has traveled beyond the frontiers of the Empire, having a profound influence on the development of art especially in the Slavic nations.
Although the catacombs were not the prerogative of any particular religious group and were widely spread geographically, they are commonly associated with Christianity.
The largest body of catacombs was discovered in Rome.
Starting with the 3rd Century Roman Christians buried their dead in extramural subterranean tombs composed of networks of corridors and cubicles of various sizes.
Some of the tombs were decorated with a painted or carved inscription identifying the occupant, while other images included scenes from the Old Testament.
The images in the catacombs are simple, made with few brush strokes and a narrow range of colors.
Subjects range from Christ carrying a lamb to three young men praising God from the fiery furnace, to the raising of Lazarus, to the Eucharistic meal.
During the time when Christianity became tolerated, the decorations of the catacombs became quite elaborate.
Source : Dormition of the Theotokos Monastary, Rives Junction, Mich. 16 #2 Author: unknown THE ICON -- HISTORY, SYMBOLISM AND MEANING The Orthodox Church is inconceivable without icons, lit candles and burning incense.
The Orthodox Church is a Church of tradition, and the presence and use of icons in the Orthodox Church is a reflection of this tradition.