The term 'icon' comes from the Greek word Eikona, which simply means image. We have 2 different styles of icons such as, fresco ( painted directly on the wall or on canvas ) or mobile icons painted on wood for either the iconostasis or generally as decoration within church or house.
Take your time in exploring Eleftherios's Foulidis work, on the two different types of iconography.
Mainly he has painted fresco at the Greek Orthodox Church of St John the Baptist and the Greek Orthodox Cathedral of the Holy Cross and St Michael in North London, and the Orthodox Community of the Highlands in Scotland.
Mobile icons, including icons for the iconostasis he painted at: