Peer review is a common practice in academic research. When a researcher has a new study or new research results to share, they submit a draft of an article to a journal or a book publisher. Other scholars who work on the same topic are asked to read the draft article and give feedback on the article's literature review, the way the research was done, and the results that the author(s) think they have found. This feedback is sent to the journal or book's editor(s), who decide whether the article should be published. The editor can also require the author(s) to revise their draft and try again.
To find out whether a specific journal uses peer review, find the journal's website. This information will usually be on the "About" page or the "Instructions for Authors" page.
Many journals use a type of peer review called double-blind or double anonymous. This means that the reviewers do not know who wrote the draft article, and the authors do not know which reviewers gave feedback. This is believed to make reviewers more honest, and to make it more likely that articles are published because they are high-quality and not because their authors are well-known.
Some journals use single-blind or single anonymous review. Sometimes, this means that the reviewers know who wrote the article. Other times, it means that the authors know who wrote the reviews. The journal's website should have more specific information.
Some journals use unblinded or open review. This means that the reviewers know who wrote the article, and the authors know who wrote the reviews. Sometimes, the reviews are also published when the article is published.
This video gives a more detailed explanation of peer review: