There are 150 Psalms. The Book of Psalms is the central book of the Bible. It is one of the most significant, most personal and most rewarding books of the Bible.
Psalms is organized into five 'books', with a doxology closing each book. Book 1= Pss 1-41. Book 2= Pss 42-72.Book 3= Pss 73-89. Book 4= Pss 90-106. Book 5= Pss 107-150).
This collection of poems and song were used in public worship in Israel. It was called sepher tehillim (book of praises).
Essentially the theology of the psalms is relational. The psalms draw attention to the relationship with God experienced by his people as they go through this life. The psalms model intimacy with God and show us how to relate any situation in which we may find ourselves to the Lord.