<human>:  What is the history behind the poetic form of haiku?
<bot>: Haiku is a traditional form of Japanese poetry that consists of three lines and a seventeen-syllable count. The origin of haiku dates back to the 9th century when it was first developed by the Japanese poet, Matsuo Bashō. The form and structure of haiku has changed little since then and is known for its focus on nature, as well as its use of symbolism, metaphor, and simplification. Bashō's work is still held in high regard and is used by many poets today as a source of inspiration.