In your literature search, you may find many types of information resources including journal articles, conference papers, books and web pages from a variety of information sources. You need to evaluate how appropriate and reliable these sources/resources are for your research and assignments. In addition, you should search and read broadly in a subject area to develop a comprehensive understanding of your research topic, and try to identify highly relevant and credible sources for your literature review.
RADAR is an acronym representing a framework for evaluating information sources to determine whether or not they are appropriate for your research.
References:
Mandalios, J. (2013). RADAR: An approach for helping students evaluate Internet sources. Journal of Information Science, 39(4), 470-478.
Check this library tutorial video about the Peer Review Process.
Many databases let you limit to peer-reviewed papers. We also use Ulrich's Periodical Directory to find out if a journal is peer reviewed.
Use the Journal Citation Reports database to find a journal's Journal Impact Factor (JIF) and the rankings of journals in many subject areas.