PDF supports the use of two different types of metadata: description and structural. Descriptive Metadata, also known as Document Properties due to the use of that term in Adobe Reader, is very useful for helping to describe the contents of a PDF. It includes such information as Title, Author, Subject and Keywords.
Debenu PDF Maximus makes it insanely easy to add document properties to one or thousands of PDFs. Watch the video below to see just how easy it is!