What is commonly a key feature of academic journals?

A key feature of academic journals is that they include peer-reviewed research findings. This process of peer review ensures that the research published has undergone rigorous evaluation by experts in the field before it is made publicly available. It serves as a quality control mechanism that helps maintain academic integrity and credibility. In such journals, articles typically present original research, reviews, or theoretical studies that contribute to the body of knowledge in a specific discipline.

The other options do not align with the primary focus of academic journals. While news updates are more often found in popular media, and entertainment content is typically associated with magazines or blogs, product advertisements are not a standard component of academic journals, which prioritize scholarly content over commercial interests.