For the sake of simplicity and clarity, the application and this site use the following terms which are worthy of a detailed explanation:
List. This implies List and Library. A SharePoint library is effectively a list with a document attached so this term is used to refer to both. A report called List Versioning may therefore include both list and library versioning details. If exceptions to this rule occur they will be clearly stated in each instance.
Item. This includes any object that may occur in a list or a library and therefore includes documents as well as calendar events or tasks. Duke is only intersted in the item or document properties and never access the document itself. This avoids the need to provide (amongst other things) reports with column headings such as Number of Documents or Items.