It is a grouped set of lines within a poemn which in poetry recieves the name of "stanza". Stanzas can have regular rhyme and metrical schemes. This are called the "stanzaic forms". Some of those forms are simple, for example four-line, and they recieve the name of quatrains. Heroic Quatrain is an old-fashioned of poem narrative consisting of four lines of iambic pentameter rhyming alternately.There are fifteen possible rhyme schemes, but the most traditional and common are: AAAA, ABAB, and ABB.