First, what the Book of Mormon is not. It isn’t a book about Mormons. Neither is it a ‘Mormon Bible’ - a substitute for the Bible of the Christian world. It is not allegory. Nor is it primarily a history.
Otterson explains that members of The Church of Jesus Christ of Latter-day Saints are “literate and knowledgeable” about the Bible and believe the Book of Mormon complements that body of sacred scripture.
The subtitle of the Book of Mormon is “Another Testament of Jesus Christ.” And it works together with the Bible to affirm and teach about him. Mormons believe that both compilations were written under the inspiration of heaven and serve us in profound ways. Most Latter-day Saint homes have at least one copy of the Bible, probably several.