An icon in the Eastern Orthodox Church is a visual representation of a holy person or event. 

These images are a very important part of what is called Holy Tradition in the Church and are venerated (not idolized) by the faithful. Holy icons like, Holy Scripture, are an expression of Divine Revelation, and when describing their making, the verb "written" instead of painted is often used. Thus, upon viewing and contemplating them, as in reading the Bible, it is hoped the faithful believer would be transfigured into a spiritual closeness with God.