In literature, a serial is a printing or publishing format by which a single larger work, often a work of narrative fiction, is published in smaller, sequential instalments. The instalments are also known as numbers, parts, fascicules or fascicles, and may be released either as separate publications or within sequential issues of a periodical publication, such as a magazine or newspaper.

A periodical literature is a published work that appears in a new edition on a regular schedule. The most familiar example is a newspaper, but a magazine or a journal are also examples of periodicals. These publications cover a wide variety of topics, from academic, technical, trade, and general interest to leisure and entertainment.