Asset Library
An organized collection of visual or multimedia resources kept accessible across design projects.
In practice
An asset library keeps a team's reusable pieces in one organized, searchable place, often shared inside the design tool so everyone pulls from the same source. Good libraries have clear names, categories, versions and notes on usage. A studio working for a restaurant chain might keep approved photos, menu icons and logo files in one library, so a new designer never picks up an outdated logo.
Often confused with Asset
An asset library is the shared collection; an asset is a single item in it, such as one icon or one photo.
Try this
Sort ten files into a small library with consistent names and folders, then ask someone to find one quickly.