Makes you an informed researcher/applicant
Provides perspective by situating your work within the knowledge base (theory & practice) of your field
Supports your research idea/proposal or identifies a gap needing further research
Provides ideas for research design; for example, quantitative or qualitative approaches or instruments to use
Provides credibility to grant proposals
More on LIierautres Reviews:
Scholarly (aka academic) articles are written by and for academics, researchers, and experts in the specific topic or broader subject area of the article. Typically involves commercial or professional association publishers.
Peer reviewed (aka refereed) articles are those scholarly articles which have been reviewed prior to publication by other experts in the topic of the article. Often reviewers are external (not members of the journal's editorial staff or board).
Grey literature is material of a scholarly nature produced outside the usual publication channels. Grey literature can include government publications, think tank reports, conference proceedings, studies from nongovernmental organizations (NGOs) such as Doctors Without Borders, evaluation reports, technical reports, etc. (Example)
Grey literature can be harder to identify and find because it often isn't formally published or indexed in the databases used to find scholarly literature. Searching online, identifying likely producers of grey literature, and checking lists of references in books or articles are ways to help identify grey literature.
Reports original research or experimentation
Critically surveys and analyzes the current state of published research on a particular topic; doesn't include original research
Describes one or more theories, frameworks, models, etc. and tends not to include empirical data
Comments on or offers a perspective or opinion on a topic; doesn't require original research