The term stands for the pedigree of a particular work of art. When complete records of ownership are kept of an artwork they are also called the 'provenance'. Art historians and collectors are very concerned with having as complete records of ownership as possible in order to determine authenticity. Some artworks are easily identified, such as the Sistine Chapel ceiling. However, when it comes to other art works, the task becomes more difficult, such as some of the paintings by van Gogh, Vermeer or Samuel Palmer. In these and other cases where ownership is more difficult to obtain, it may affect the dealer who is trying to sell the piece.