Peer review is a process used for checking the work performed by one's peers. Peers means equals. A peer review is done to ensure that the work meets specific criteria. Peer review is used in working groups for many professional occupations. In academic publishing, peer review is used as a measure to find the quality of a work for publication. Peer review methods are employed to maintain standards, improve performance, and provide credibility. The principle behind peer review is that equals can identify each other's errors quickly and easily. Peer review guards against plagiarism.