A Literature Review is a thorough and methodical study of existing research information on a specific topic, presented in a well-ordered, scholarly manner.
It is an important part of your thesis, whether your thesis is by research or by publication, where you examine previous and current literature so that you can:
Different disciplines will require different sorts of literature reviews. In Arts and Humanities studies, literature may be reviewed throughout the thesis as required by the topic. For Social Sciences and Sciences research, the literature review often consists of a separate chapter that informs the research design and methods. For some topics, there may be no literature review due to the 'cutting edge' nature of the research topic.
Traditional / Narrative review - a critical summary and synthesis of previously published literature about a particular topic involves systematically exploring related literature. Narrative reviews can be organised by chronology, theme, or methodology, and may highlight issues of debate and gaps in current research.
Systematic Review - "[a] high-level overview of primary research on a particular research question. It seeks to collate all evidence that fits pre-specified eligibility criteria with the aim of minimising bias by using explicit systematic methods" - Cochrane Database. Commonly used within Health Sciences to compare and assess effectiveness of clinical interventions. Check Otago's guide on Systematic Reviews.
Scoping Review - a "preliminary assessment of potential size and scope of available research literature. Aims to identify nature and extent of research evidence (usually including ongoing research) (Grant & Booth, 2009)."
Grant, M. J., & Booth, A. (2009). A typology of reviews: An analysis of 14 review types and associated methodologies. Health Information and Libraries Journal, 26(2), 91-108. https://doi.org/10.1111/j.1471-1842.2009.00848.x
The Cochrane Handbook for Systematic Reviews of Interventions is a very detailed, high level approach used when undertaking a Cochrane review - the highest level of evidence on which to base clinical treatment decisions.
If you are simply wanting to apply a systematic approach to your literature review, you may want to choose one of the other options e.g. PRISMA, which provides an evidence-based minimum set of items for reporting in systematic reviews and meta-analyses.
e.g. Scoping Review - a "preliminary assessment of potential size and scope of available research literature. Aims to identify nature and extent of research evidence (usually including ongoing research) (Grant & Booth, 2009)."
In order to write an excellent literature review, you will need to find all the relevant literature on your topic. This is an iterative process that might involve:
Your Subject Librarians can help you with all these steps.
Once you have found on topic literature, you will need to read it closely and critically evaluate both its rigour and its relevance to your work. Think about :
Have you ever wondered how to keep track of new and upcoming research relevant to your topic, so that you are not horribly suprised by that article that pips you to your PhD post?
Well, Email Alerts are the most common and reliable way of having research notifications come to you, rather than the other way around:
Succeeding with your literature review: A handbook for students
Systematic Approaches to a Successful Literature Review
The literature review: A step-by-step guide for students
Telling a Research Story
Conducting Your Literature Review by 
Systematic reviews to support evidence-based medicine: How to review and apply findings of healthcare research (2nd ed.)
Doing a Systematic Review
Reviewing Your Research Methods
Sage Research Methods enables you to search relevant books, book chapters, dictionary and encyclopedia entries, videos, or journal articles from over 175,000 pages concerning research methods. It also provides a visual Methods Map to help you find new methods or discover relationships between methods, and link to related content.
