This document discusses altmetrics, which are alternative metrics for measuring the impact of scholarly research beyond traditional citations. It outlines some limitations of traditional metrics like journal impact factors. With more globalized and networked research, altmetrics can track how research outputs are viewed, downloaded, cited, shared, commented on, and reused across various online platforms and sources. This provides a more comprehensive and faster assessment of impact that is relevant to more diverse audiences. Altmetrics are relevant for librarians because they support roles in scholarly communications, research assessment, and collection development. However, altmetrics also have limitations and open questions around gaming, interpretation, and applicability across disciplines.