The following characteristics can identify a source as scholarly:
Peer review is a process through which some scholarly articles and book chapters are critically evaluated by experts with in-depth knowledge of the research area before publication in order to ensure the information is valid, credible, well-written, and of high quality.
Are you looking especially for peer-reviewed journal articles? See Verifying Peer Review.
Because scholarly sources are well-researched, written by experts, and discuss topics in great depth and detail, they have credibility and authority. Using scholarly sources in your own research gives your work credibility and authority, as well. Non-scholarly materials can also be useful and appropriate for some academic purposes, but generally scholarly sources are expected in academic research.
Other sections in these Get Started with Library Research guides discuss how to find scholarly sources. See the Find Information section, especially the Find Articles and Find Books pages. The Subject Guides may help, too. They point you toward recommended resources in each subject area, through which you can find scholarly sources.
Need more help with this? Ask a Librarian.