Peer review refers to the evaluation of scholarly outputs (articles, books, preprints, etc) by others working in the same field. Reviewers inspect research quality and originality, data validity, and author conclusions in order to provide a "stamp of approval" from the research community for the work under review.
Many resources are available to help researchers learn how to effectively peer review. A select few publisher-based trainings are listed here. They are online and most are free upon registration.
The concept of "open peer review" is an umbrella term for the many ways that models of peer review can be adapted to adhere to Open Science aims (see this systematic review). These include making reviewer and author identities open, publishing review reports, and encouraging diverse, equitable, and inclusive participation in the peer review process.
Explore these resources to learn more: