Haiku(俳句、ハイク) Shortest fixed syllable form(5-7-5) of Waka, that should use Kigo（季語、season words）.

Relational words;
Waka（和歌、ワカ） Japanese classic poem, including various forms.
Tanka（短歌、タンカ） Short fixed syllable form(5-7-5-7-7) of Waka.
Haikai（俳諧、ハイカイ） Same meaning as Haiku.
Senryu（川柳、センリュウ） Same format as Haiku. but not required Kigo.
Renga（連歌、レンガ） Dialogical continuum poem.