Metadata is a term that refers to the data that is collected, organized, and stored data in order that the data may be categorized and used in relevant ways for further research by other users. In fact, metadata is often quite simply defined as being “data about data”.
Metadata is often referred to as descriptive metadata in order to differentiate it from structural metadata which describes and defines “data about the containers of data”. Metadata is used in a number of information storage applications, both online and in the real world. Metadata is often standardized, with different sets of standards applying to different disciplines. The standardizing bodies often differ by discipline as well.
Metadata is most commonly associated with Library and Information Sciences, with the traditional card catalog being one of the oldest forms of metadata in the world. The Dewey Decimal system is, in fact, a classic system of metadata management as it records data about the books stored in a library and arranges that information in a searchable way. Metadata, which is also referred to as meta-content in this context, includes the recording of information such as the author’s name, the date of publication, the place of publication, the publisher’s name, and a brief abstract of the work’s content. Metadata standards in a library and information science context are standardized by bodies such as the Library of Congress.
In an increasingly digital world, it is not surprising that online materials, including articles and images, are organized by metadata as well. Most web pages have metadata written into them, often called meta tags, which provide short descriptive phrases about the site’s content. These meta tags are key to the functioning of search engines which use them to determine which sites the best match a searcher’s query. Online articles also usually contain metadata similar to that used in library systems, including the author’s name, date of publication, and reference materials.
Photographic images are usually embedded with metadata as well, a process that has been rendered standard in recent years due to the rapid growth of digital photography. Digital cameras usually come with software that automatically encodes the image with metadata such as exposure details, camera model, and time of capture. Most digital photography programs also allow the photographer to embed the image with further descriptive data, including names and geographical information. Images that are posted online also have metadata written into them, typically in the form of meta tags for search engine optimization. This is similar to that for digital photographs, and often includes descriptive information such as a date, names, and location.
Other forms of media such as music and videos are also organized along to the standards of metadata information collection. This is especially the case for digital music and video files available online which are practically invisible to search engines without meta tag descriptions. Metadata collection standards are also applied to data gathering in academic and research contexts such as environmental research, healthcare, and legal research and record-keeping. Metadata standards allow people to search for information effectively by using a system of categorization that describes the data contained within a collection or on a site. Without metadata, all the information our global society has amassed over the years would be nothing more than a Gordian Knot of impenetrable data, impossible to make sense out of.