This short video explain the terms scholarly/academic and peer-reviewed/refereed.
If you found a source via the internet at large or via Google Scholar, it won't be clear whether the article is from a peer-reviewed journal.
You can use the directory below (Ulrich's Web) to check whether the journal the article is published in is a peer-reviewed journal or not.
You can also enter the title of the article into LibrarySearch and if turns up there, if it's from a peer-reviewed journal, it should have a "peer-reviewed" label indicating this. Non-peer-reviewed scholarly journals are still reliable, there is normally always an editorial process but it may differ from the established "peer-review process".