The terms narrative review and literature review may be used interchangeably. Narrative reviews are used to summarize the most relevant research on a topic.
Why would you do a narrative review?
You have only one person to work on the review: yourself!
You are not developing a protocol to guide your review of the literature
A reproducible and comprehensive search strategy is not necessary for the purposes of your review
You only wish to highlight the most influential literature to provide background on a topic