Term of the Moment
drive-by download
Definition: metadata
(1) (The Metadata Company, LLC) A California software firm that offered data management products. In 1986, the company was granted incontestable status for the Metadata trademark, and years ago, Metadata's lawyers threatened litigation if anyone, including this Encyclopedia, used that term spelled as one word. As a result, we changed the spelling of the generic meaning (definition #2 below) to "meta-data" and kept that spelling for many years. As of 2023, the Metadata company is no longer in business, and a search for "metadata" as one word on Google and Bing delivers hundreds of millions of results.
(2) Data that describes other data. For example, data dictionaries and repositories provide information about the data elements in a database (see data dictionary). Digital cameras store metadata in the image files that include the date the photo was taken along with camera settings (see EXIF). Digital music files contain metadata such as song title and artist name (see ID3 tag). Metadata are stored in an HTML page (Web page) to help search engines define the page properly, and most especially, make it rank higher in the results list (see meta tag).
A Glaring Lack of Metadata - Music CDs
Music CDs were initially designed without metadata, such as album name, song titles and artist names. In the early 1980s, readouts on CD players were expensive, and although a few thousand bytes could have easily been set aside in the CD format for future albums to take advantage of, no such accommodation was made. When CDs were played on the computer, a solution to display the metadata was a circuitous search over the Internet based on the track length of each song. When metadata was finally added, many old CD players could not play them. See CDDB.
Metadata in the Snowden Debacle
After former CIA employee Edward Snowden leaked top-secret American surveillance programs to the press in May 2013, metadata came front and center. It was revealed that the U.S. National Security Agency (NSA) had undertaken massive phone surveillance, and the controversy was about what was recorded: the actual voice conversations or only the metadata (times and telephone numbers of the calls). Even when voice content is not recorded, the metadata can be analyzed to determine who might be in contact with suspected terrorists.
Metadata in an Image File
A Ton More
(2) Data that describes other data. For example, data dictionaries and repositories provide information about the data elements in a database (see data dictionary). Digital cameras store metadata in the image files that include the date the photo was taken along with camera settings (see EXIF). Digital music files contain metadata such as song title and artist name (see ID3 tag). Metadata are stored in an HTML page (Web page) to help search engines define the page properly, and most especially, make it rank higher in the results list (see meta tag).
A Glaring Lack of Metadata - Music CDs
Music CDs were initially designed without metadata, such as album name, song titles and artist names. In the early 1980s, readouts on CD players were expensive, and although a few thousand bytes could have easily been set aside in the CD format for future albums to take advantage of, no such accommodation was made. When CDs were played on the computer, a solution to display the metadata was a circuitous search over the Internet based on the track length of each song. When metadata was finally added, many old CD players could not play them. See CDDB.
Metadata in the Snowden Debacle
After former CIA employee Edward Snowden leaked top-secret American surveillance programs to the press in May 2013, metadata came front and center. It was revealed that the U.S. National Security Agency (NSA) had undertaken massive phone surveillance, and the controversy was about what was recorded: the actual voice conversations or only the metadata (times and telephone numbers of the calls). Even when voice content is not recorded, the metadata can be analyzed to determine who might be in contact with suspected terrorists.
A huge amount of metadata can be stored in an image file. The IPTC Core section (expanded below) is a metadata standard from the International Press Telecommunications Council for adding creation data.
An image file can be edited to include a huge amount of metadata to describe the file. DICOM stands for Digital Imaging and Communications in Medicine.