'Fragments' often referred to as 'Frags' (alongside Items are one 'atomic' particles of data in ARK. Fragments contain snippets of the data for a record which broadly corresponds with the idea of a column or field in a normal database. Each fragment is represented by a single row in one of the Data Class tables in the database and is indentified by a unique row id or 'Fragment ID'. Each Fragment must be linked to either another Item by its itemkey/itemvalue pair, or to another fragment in what is termed a Chain. In the case of chains, the itemkey/value pair is filled with the table name/fragment id of the linked fragment.
Fragments contain the pieces of data that go to make up a record, this might be snippets of text or dates or linked Actors undertaking an action. Within each Data Class different types of teh same fragment are identified by Class Type.