SharePoint stores all data in lists and libraries. Put simply, lists can be considered data structures that store data in the form of rows and columns. SharePoint libraries are lists that store documents along with information about the document. While internally lists and libraries store data in Microsoft SQL Server, lists and libraries abstract the database. As a SharePoint developer, when working with data you will find yourself working mainly with SharePoint lists and libraries as the back end. Although there is a difference between SharePoint lists and libraries, this hour refers to both as SharePoint lists unless specified otherwise.