A literature review is a study which:

• is based on database searches
• summarises the results of research
• has the aim of objectively discussing a specific topic or theme.

There are many types of literature review, but two of the main ones are:

• narrative (or traditional) review
• systematic review.

The image above describes common review types in terms of speed, detail, risk of bias, and comprehensiveness.

For more information on all types of literature reviews, see the Library's Literature Review guide. This guide includes a wealth of information on all types of reviews.

For more information on systematic reviews, see the Library's Systematic and systematic-like reviews guide.

[Image attribution: "Schematic of the main differences between the types of literature review" by Brennan, M. L., Arlt, S. P., Belshaw, Z., Buckley, L., Corah, L., Doit, H., Fajt, V. R., Grindlay, D., Moberly, H. K., Morrow, L. D., Stavisky, J., & White, C. (2020). Critically Appraised Topics (CATs) in veterinary medicine: Applying evidence in clinical practice. Frontiers in Veterinary Science, 7, 314. https://doi.org/10.3389/fvets.2020.00314 is licensed under CC BY 3.0.]