A publication is considered to be scholarly if it is authored by academics for a target audience that is mainly academic, the printed format isn't usually a glossy magazine, and it is published by a recognized society with academic goals and missions. A publication is considered to be peer-reviewed or refereed if its articles go through an official editorial process that involves review and approval by the author's peers (experts in the same subject area). Most (but not all) scholarly publications are peer-reviewed.
Discovery Search and some databases, like those provided by EBSCOhost and ProQuest, allow searching to be limited to peer-reviewed publications. Look for the limiter option on the advanced search screen. Once applied, all of your search results will be scholarly or peer-reviewed publications. See also the following FAQ for the Discovery Search limiter option.
If you already have an article citation, or your database does not allow limiting to peer-reviewed articles, you can lookup to see if the journal where the article appeared is peer-reviewed/scholarly. Use the UlrichsWeb database and search using the journal title (not the article title) from your citation. Look for the Document Type and Refereed fields to determine if the journal in question is peer-reviewed.