A by-line is the short line in a newspaper or magazine that tells you who wrote the article. You usually see it under the title, in the shape “by Chen Wei.” Writers care about it because it is their name on the work; a young reporter may wait a long time for a first by-line. People also write it as one word, byline, especially in American English. The word belongs to newsrooms and magazines; you would not use it for the name on a school essay. Though actually the line can sit at the top or, in some papers, at the end — what makes it a by-line is that it names the writer, not where it sits on the page.