AEM Assets is an application on the AEM Platform that allows our
customers to manage their digital assets (images, videos, documents and
audio clips) in a web-based repository. AEM Assets includes
Metadata-support, Renditions, the Digital Asset Management Finder and
the AEM Assets Administration UI. Review here for more FAQs -
https://helpx.adobe.com/experience-manager/6-4/assets/using/medialibrary.html
Thanks.