Article level metrics reflect the impact of a specific piece of research and may be a more useful addition to your resumé or grant application than journal impact or rank, i.e. the Journal Impact Factor (JIF) of a journal does not describe the impact, importance or quality of any individual paper.
Traditional scholarly citation metrics reflect an article's long-term contribution to the scientific literature. Citation counts are available for articles submitted to scholarly journals in citation databases and other sources such as Google Scholar:
Alternative metrics, or social impact include other impacts of a work, such as the number of article views, numbers of downloads, or mentions in social media and news media.
Alternative metrics will normally be available earlier than traditional citation metrics, which are dependent on journal publishing cycles.