The Book of Psalms in the Bible consists of 150 prayers traditionally ascribed to the authorship of King David (though there were likely a good number of our ancestors who contributed to the collection). They are clearly the inspired Word of God and they express a whole range of human emotions, ranging from joy and suffering to the fullness of life to fear of dying.
The Psalms are inspired songs which teach us how to speak to God, expressing ourselves and the whole range of our human experience with words that God Himself has given us. As such, the Psalms can teach us how to pray and Pope Benedict XVI once said that they make up a “prayer book par excellence.”
The Psalms are also quite different from the other books of the Old Testament. Instead of being narratives with a specific meaning or purpose, they are given to us quite literally, as Pope Benedict said, as texts for prayer. Although they express a diversity of prayer forms, the Psalms are generally marked by the two interconnected dimensions of humble petition and of praise addressed to a loving God who understands our human frailty.
For an intriguing look at the Psalms: https://youtu.be/UADk6L4RfZU