Scholarly and Peer-Reviewed sources are very similar. 'Scholarly' means the article was written by an expert for an audience of other experts, researchers, and students. 'Peer-reviewed' means the article was reviewed and critiqued by the author's peers, who are experts in the same subject area. Peer-reviewed articles are always scholarly, but a scholarly article may or may not be peer-reviewed. However, the vast majority of scholarly articles are  peer-reviewed, so the terms are used interchangeably.