SharePoint Libraries share the same characteristics as SharePoint lists such as
columns, views, and validation to name a few. What distinguishes SharePoint
libraries is that each item in a library has a underlying document. So in
addition to the data stored in library columns, the document stores its own data
based on the type of document. Because of the extra data that can be stored in
columns that can be used to filter and search by and features such as versioning, libraries are considered a great replacement for the more traditional file server system. Libraries are, like lists, a
fundamental building block in a SharePoint site.