Your teachers will often ask you to use scholarly sources for your papers and projects. Many of the Library's databases consist entirely of scholarly articles, for instance, JSTOR, PsycArticles, and Medline. Nearly all the other databases have an option on the search screen to limit your search to all scholarly (all peer reviewed) results.
But what is it about a book or an article that makes it scholarly? "Scholarly research" boils down to a system for verifying facts and logic. It's a set of checks and balances to prevent errors, nonsense, and lies from being passed off as good information. A scholarly researcher first learns the ideas and findings of others in the field. The researcher then develops a hypothesis and designs and implements a methodology to prove or disprove that hypothesis.
Scholarly also means "by scholars and intended to be read by other scholars." Popular sources have articles that are intended to be interesting and comprehensible for as many people as possible. They have to leave out some details and simplify others. Scholarly sources have more detailed, advanced, sophisticated information. And it's closer to the source, not translated for you by another non-expert
