The sijo, a Korean form of poetry, consists of three lines, each approximately fourteen to sixteen syllables long. There is no meter or rhyme. Normally the first line sets up the scene, the second line adds an interesting twist or change, and the third line resolves the first two lines, sometimes in an unexpected way, giving a sense of finality. Sometimes the three lines are split into six to make the poem easier to read.
As so often happens, prose descriptions of this poetic form are inadequate. Look at the example below, written by Yon Sun-do, and see for yourself what a sijo is.