Macedonian orthography is phonemic with a correspondence of one grapheme per phoneme. The grapheme above represents a voiceless uvular fricative. The digraph "ch" and the grapheme "w" are preserved. The terms "glyph", "sign" and "character" are sometimes used to refer to a grapheme. Allographs can vary vastly, without affecting the underlying identity of the grapheme. The same Greek root also appears in graphics, grapheme, and photograph. Some German publications also use a grapheme (). There exist two main opposing grapheme concepts. A "grapheme" is a specific base unit of a writing system. A bar or stroke is a modification consisting of a line drawn through a grapheme.