Algorithmic amplification describes increases in the distribution or visibility of content on digital platforms, arising from a combination of automated ranking by recommendation systems and users' own sharing. Definitions differ over the baseline used to determine whether content has been amplified, and separating the contribution of ranking from that of users is a recurring difficulty in the research. Major platforms, including Facebook, YouTube, TikTok, and X, use such systems to determine what appears in users' feeds and search results. The term is used in research on social media and digital media regulation to describe how platform design choices influence the distribution of online information.