A haiku is a traditional Japanese poetic form. It consists of three unrhymed lines with specific syllable counts: five syllables in the first line, seven syllables in the second and five in the third. Haikus are often about nature and the seasons.
A sonnet is a 14-line poem with a set rhyme scheme and a particular syllable pattern called iambic pentameter. Different types of sonnets have different rhyme schemes. An English, or Shakespearean, sonnet usually follows the rhyme scheme of: ABABCDCDEFEFGG. The final two lines, a couplet, summarize the main idea of the poem.
According to the passage, one of the differences between haikus and sonnets is