The Ancestral File [AF] is part of FamilySearch program’s general Tree search. It is a database that contains significant genealogical information such as lineage names, birth dates, birth places, deaths and marriages of millions of people. It is an online research tool containing information contributed by LDS members around the world. It currently contains about 40 million records allowing you to view records on individual basis. It lets you know how much information people may have about your family. You can search about your ancestors in the pre-1500 period because compilations of pedigrees existing around that period done by the Medieval Unit of the Family History can be found here. Once it is fully established, you would be able see the name and address of the person who contributed the information. PAF files are files of data created from this software. On Windows, you may open these files using the software or the application RootsMagic.