Anything archival relates to an archive, which is a record or collection of historical materials. Archival resources document the past. Most libraries have a special place for archival documents, like old newspapers and photos.
An archive is a collection of older things such as books, music, or documents. Many librarians and curators collect and care for archives. Anything archival relates to an archive. An archival record documents everything in an archive, such as an archive of 19th century poetry. An archival search is a search of an archive, such as an archive of birth certificates. This word has to do with historical collections. Scholars who study the past often have to do archival research.