The characteristics of haiku poetry are all centered on the number of syllables and structure of the lines. The first line should contain 5 syllables. The second line should contain 7 and the third line should contain a final 5 syllables. Subject matter and theme are left solely to the creative imagination of the author.
Created by the Japanese, Haiku is a lyric verse poetry. It is limited to three lines. To be considered a haiku these perimeters must be followed: 5 syllables in the first line, 7 syllables in the second line and 5 syllables in the last sentence. The poem does not have to rhyme.
Haiku originated from Japan where it is often, but not always, 17-on. "On" is a counting system for the sound units in the Japanese language system(s) which are non-syllable and non-alphabetic. An English-language (EL) haiku will often shadow the brevity with around 12 ELsyllables, with a short/long/short line format.