So, the lit review is an integral part of the research process that helps you:
fully understand your topic
develop your own research ideas
demonstrate your knowledge
It's part of what's called the "scholarly conversation," the network of research studies that tell the story of relationships and connections in a discipline. Your research will become part of this conversation.
Literature reviews may appear as the introduction to a journal article or as an in-depth "review article" or as part of a graduate student's dissertation or thesis.