What has fourteen lines and a set rhyme scheme?

A Sonnet typically has fourteen lines and a set rhyme scheme. There are two main types: Italian (Petrarchan) with an octave (abbaabba) and a sestet (cdecde or cdcdcd) rhyme scheme, and English (Shakespearean) with three quatrains (abab cdcd efef) and a final rhymed couplet (gg).