Peer review is defined as obtaining advice on individual manuscripts from reviewers expert in the field who are not part of the journal’s editorial staff. The process may vary in scope and execution. Grant proposals, preprints, journal articles, books and conference submissions may all be subjects of peer review, with the goal of building trust in the validity, accuracy and quality of the work.
This video gives an overview of the process of peer review and why it matters in academic research. (North Carolina State University, 2014, 3:15 mins)