Always know what you are searching whether you are searching an online database or a printed book.
The “Restored” marriage records shown in the image are from a variety of local sources. They are referred to as “Restored” because the original records from the county were destroyed in a fire.
Always read the preface or any introductory material in order to determine exactly what you are searching or using. That’s the only way you will know whether that next book on the shelf is something you need to use or not.