Haiku is a form of traditional Japanese poetry that adheres to strict rules. The entire poem is short containing only 17 syllables in 3 lines. The first line must be 5 syllables, the second lines is 7, and the last line is 5 again, giving the poem a graceful meter. Traditionally the poetry will make reference to the season, and most often it pertained to winter which is why this holiday is on the Winter Solstice.
Obviously well known traditional Japanese Haiku when translated to English will not necessarily have 17 syllables, but by reading some of them, you will get the idea of the imagery associated with this form of poetry.
* Night; and once again,
* the while I wait for you, cold wind
* turns into rain.
Masaoka Shiki
* The crow has flown away:
* swaying in the evening sun,
* a leafless tree.
Soseki Natsume
* The moment two bubbles
* are united, they both vanish.
* A lotus blooms.
Kijo Murakami
To learn more about Haiku, or to learn to write some of your own, try some of these books available at Amazon.