In art and archaeology, sculpture and painting, a register is a horizontal level in a work that consists of several levels arranged one above the other, especially where the levels are clearly separated by lines. Modern comic books typically use similar conventions. It is thus comparable to a row, or a line in modern texts. In the study of ancient writing, such as cuneiform and Egyptian hieroglyphs, "register" may be used of vertical compartments like columns containing writing that are arranged side by side and separated by lines, especially in cylinder seals, which often mix text and images. Normally, when dealing with images it only refers to row compartments stacked vertically.