Mosaic is an art form which involves fitting small pieces of rock, shell, tile, or glass called tesserae together to create a pattern which may be abstract or representational. Some of the finest examples of mosaic can be found in ancient art from the Greco-Roman world, and in Byzantine churches. This craft can be used to decorate everything from chests of drawers to floors, and it has been a part of the artistic expression of many cultures all over the world.