Religious lyric poetry reflects the inner feelings of the person whose soul is stirred by thoughts of God. The Psalms are thus inspired responses of various individuals to God's revelation of Himself in the Old Testament era. The titles are not a part of the original inspired documents. The Psalms were composed over a span of about one thousand years. Unlike our modern poetry, which is designed to rhyme, Hebrew poetry is characterized by a rhythmic arrangement of thought patterns.
Scholars distinguish several types of parallelism.
There is, for instance, Synonymous Parallelism. There is also Antithetic Parallelism in which the second line is set in contrast to the previous line. For example, in Psalm 119 each section of eight verses begins with a sequential letter of the Hebrew alphabet. This arrangement may have been intended to facilitate memorization. At some point in antiquity, the Psalms were divided into five sections, which are still reflected in our modern Bibles.