Summary of The Book of Psalms
Psalms is divided into five books : Psalms 1-41, which witness
to David's life and faith; Psalms 42-72, a group of historical
writings; Psalms 73-99, ritual psalms; Psalms 90-106,
reflecting pre-captivity sentiment and history; and Psalms
107-150, dealing with the captivity and return to Jerusalem.
These five books are often regarded as the devotional
counterpart to the five books of Moses (Genesis, Exodus,
Leviticus, Numbers, Deuteronomy).
Link: https://bible-history.com/old-testament/bookofpsalms