Your lecturers will often require that in assignments you use information from academic journal articles that are peer reviewed (an alternative term is “refereed”).
Peer review is a formal quality control process whereby an article submitted to a journal is evaluated by several recognised experts in that discipline. These “referees” judge whether it makes a sufficient contribution to knowledge in the discipline and is of a sufficient standard to justify publication.
Academic book manuscripts, conference papers, trade journals can also be commonly peer reviewed. Many library databases, including Discover, allow you to limit your search to only peer reviewed articles.
In the diagram below, "Fuel Cell" is a non-peer reviewed magazine, whereas "Cell Proliferation" is a peer reviewed journal, as indicated by the Referee Jersey icon to the left of the title.