A sonnet is a 14-line poem usually associated with Shakespeare, who wrote more than 150 of them.
Structure
A sonnet has 14 lines broken up into three four-line stanzas and a two-line stanza at the end that closes out the poem.
Each line has 10 syllables.
It has an alternating rhyming structure that looks like this:
abab
cdcd
efef
gg
That means that the first and third lines of each stanza rhyme, and the second and fourth lines of each stanza rhyme. The last word of the final two-line stanza, also known as a couplet, should rhyme, as well.