It is concentrated in the Psalms, the wisdom books, and the prophets, but sprinkled throughout. Because of the separation of time and culture, much of the poetry poses questions for the modern reader. It is hard to define biblical poetry. It is often marked by parallelism, but not always. Thus, many are beginning to see prose and poetry on a continuum, with distinctions being fluid, not absolute.
Poetry tends to make greater use of parallelism, imagery, etc.
While prose represents a certain departure from normal speech patterns, poetry departs even further. Poetry is more self-consciously structured. Higher level of literary artifice. Major conventions are terseness, parallelism, and imagery. Terseness Hebrew poetry is short and to the point.