Note: Do not rely on this information. It is very old.
Sonnet
Sonnet, a short song of fourteen lines, generally containing a single idea or sentiment. It seems to have first appeared in Italy, perhaps in Bologna, in the 13th century, and later in other countries. The kinds are chiefly two: the simple stanza (as Shakespeare's), and the compound stanza (as Petrarch's). The simple stanza consists of three quatrains of lines rhyming alternately, and ending with a couplet; the compound of eight lines rhyming 1,4,5.8: 2,3,6,7: and six lines of two or three rhymes, varying in order. Among English writers of sonnets are Shakespeare, Drayton, Keats, Wordsworth, and Milton.