Haiku is a type of poem that keeps its simplistic, image-filled form rooted deep in its original thirteenth-century Japanese roots. This pared down poem introduced the Japanese rega, a 100 stanza long oral poem. The Haiku is a breath long: it can be read in a breath, and it captures a single moment in time, filled with stark, vibrant imagery. The haiku is literal and can be an allusion, but it never uses figurative language such as the metaphor or simile.
Modern poets morph traditional haiku, changing the syllable count (originally 3 lines made of 17 syllables total with five syllables in the first line, 7 in the second, and 5 in the third); the use of a kigo (a word directly associated with a season, such as leaves for fall, frogs for spring, or a sun for summer); the use of present tense; and the breath (there was a pause following the first and second line).