What is a peer reviewed source?

Answer 1

Usually that term refers to professional journals in any number of disciplines. When you submit an article to a journal, it goes through a review and editing process that helps assure (but cannot always guarantee) that the material submitted is legitimate, original and substantially free from error-- that kind of thing. The process also helps to establish (for science journals, anyway) that the research was carried out competently using appropriate equipment, materials and methodology, and that the references listed are timely and appropriate.