Peer review, or refereeing, is the process by which a journal article manuscript undergoes critical evaluation from 2-3 other experts (working in the same field as the original researcher) before the journal editor makes a decision on whether to publish that article.
You can find out more about peer review from the links below.
All journals were not created equal. There are a number of statistical tools that are available to give an indication of the relative quality of a journal title. When using these tools, please ensure you are comparing journal titles within a particular subject area only, and that you are aware of the limitations of such tools.
The Impact Factor (IF) of a journal is the average number of citations per article, calculated from data from the Web of Science Core Collection. These are available via the Journal Citation Reports in the Web of Science.
The SCImago Journal Rank (SJR) accounts for both the number of citations received by a journal and the importance or prestige of the journals from which the citations are received. The Source Normalized Impact per Paper (SNIP) is the ratio of a journal title's average citation count per paper and the citation potential of its subject field. Both of these are available via the Journal Analyzer in Scopus.
The Eigenfactor uses network analysis and information theory to evaluate the influence of journal titles. These are available from the eigenfactor.org website.