This verse form was made particularly famous because Dante used it in The Divine Comedy. It requires three-line stanzas (tercets) with the rhyme scheme a b a, b c b, c d c and so on. It is much more suited to Romance languages than to English, and especially to Italian where the high frequency of vowel sounds at the ends of words makes such a structure feasible and even necessary.
Editors. "Terza Rima". The Literary Encyclopedia. First published 01 November 2001
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1095, accessed 21 May 2013.]