Metadata

Information tells us about things.

Some facts help us find things. They tell us a book's name. They show who wrote it. This helps you find what you need.

This is called metadata. It is data about other data. It describes things to help us use them. It can tell us when a file was made.

Metadata can show how things are put together. It can show how pages form chapters. It also shows who can use a file.

It can even help us find web pages. It can list the names of singers on a disc. This makes finding things much easier.

Metadata is like a label for information. It helps us keep things in order.

Metadata is data about other data. It helps us find, use, and manage information.

Think about a book. The story inside is the data. The book's title and author are metadata. Metadata makes it easy to locate things.

There are many types of metadata. Descriptive metadata helps you find things. It uses keywords, titles, or authors. Structural metadata shows how parts fit together. For example, it shows how pages form chapters. Administrative metadata helps people manage a resource. It might show the file type or when it was made.

Some metadata is for special needs. Accessibility metadata describes how to use information. It can show if a book is in large print.

This image shows a plant record. The record has the plant and metadata about it. A barcode also points to a digital record. This digital record has even more metadata.

Metadata is used in many ways. It helps web pages show up in searches. It can list the singers on a music disc. It even helps businesses understand their data. Metadata helps keep our digital world in order.

Metadata is a special kind of information. It is often called "data about data."

This means metadata describes other pieces of information. It helps people find, use, and manage data more easily. Think about a book in a library. The story inside is the main data. The book's title and author are metadata. Metadata can describe the size of a digital image. It can also show when a text document was written. Without this extra information, it might be hard to organize things.

There are many different ways metadata works. Descriptive metadata helps you find things using keywords or titles. Structural metadata shows how parts fit together. For example, it shows how pages form chapters. Administrative metadata helps people manage a resource. It can show the file type or when it was created. There is also legal metadata about who owns a work. Accessibility metadata describes how to use information for special needs. It might show if a book is in large print. Even statistical metadata describes how data was collected.

People have used metadata for a long time. Before the 1980s, libraries used paper card catalogs. These cards held metadata like the author and subject. In the 2000s, more information moved to digital formats. This required new ways to describe digital files. The term "metadata" has a history dating back to the 1960s. In 1967, David Griffel and Stuart McIntosh wrote about it. Philip Bagley used the term in a 1968 book. He used it to describe the structure of data containers. Since then, many different fields have used this helpful term.

Experts have created different ways to group metadata. Ralph Kimball divided it into three categories. These are technical, business, and process metadata. Dan Linstedt created the data vault methodology. He says business metadata defines how data is used in a company. This includes things like business requirements and timelines. NISO also recognizes three main types. They use descriptive, structural, and administrative labels. These labels help keep information clear and organized. Different industries like museums or music use their own special standards.

Metadata is all around us in our daily lives. A music CD uses metadata to list the singers. A web page uses metadata to help search engines find it. In the past, people used "metatags" to help with web searches. These tags helped search engines decide which sites were important. Even your telephone calls and emails create metadata. This can include things like the time of a call. Metadata helps the digital world run smoothly every day.

Metadata is often defined simply as "data about data." It is information that describes, explains, or locates other pieces of data. While a single data asset is finite, its metadata can be considered infinite. Metadata helps people retrieve, use, and manage information more effectively. For example, the content of a book is the primary data. However, the title, author, and publication date are metadata about that book.

Without this descriptive layer, finding specific information in a massive collection would be nearly impossible. Metadata provides the necessary context to make raw data useful.

There are several distinct types of metadata that serve different functions. Descriptive metadata is used for discovery and identification. It includes elements like titles, abstracts, authors, and keywords. Structural metadata describes how compound objects are put together. For instance, it might explain how individual pages are ordered to form chapters in a digital book. Administrative metadata helps manage a resource. This includes technical details like file type, creation dates, and permissions.

Within administrative metadata, there are sub-types like rights management metadata for copyright and preservation metadata for long-term saving.

Other specialized forms of metadata exist for specific fields. Reference and statistical metadata describe the quality and processes used to collect statistical data. This is vital for researchers who need to validate data production. Legal metadata provides information regarding creators and public licensing. A growing field is accessibility metadata. This describes the needs and preferences of users to ensure universal access. For example, metadata might indicate if a resource is available in braille or large print. Projects like Cloud4All have worked to identify gaps in how we describe these accessibility needs.

Experts have developed different models to categorize these complex layers. Bretherton and Singley (1994) distinguished between structural/control metadata and guide metadata. Structural metadata describes database objects like tables and columns. Guide metadata uses natural language keywords to help humans find items. Ralph Kimball divided metadata into technical, business, and process categories. Dan Linstedt, who created the data vault methodology, emphasized the importance of business metadata. He noted that business metadata defines functionality, requirements, and timelines. This helps business people understand how data is used within a company.

The history of metadata spans several decades of technological change. The term itself has roots in the 1960s. In 1967, David Griffel and Stuart McIntosh wrote about metadata in computer science. Philip Bagley is credited with coining the term in his 1968 book, "Extension of Programming Language Concepts." He used it to describe the structure of data containers. Before the 1980s, metadata was often physical, such as the cards in library catalogs. As libraries converted to digital databases in the 1980s, metadata became digital. By the 2000s, metadata standards became essential for managing the massive increase in digital information.

In the digital age, metadata is integrated into almost every medium. A music CD contains metadata about the singers and songwriters. A digital image might include its resolution, color depth, and shutter speed. Web pages use metadata to tell search engines what the page is about. In the late 1990s, "metatags" were a primary factor in web searches. However, their use decreased because of "keyword stuffing," where people misused tags to trick search engines. Today, metadata is also collected by governments regarding telecommunications. This includes information about internet traffic, email subject lines, and cell phone locations.

Metadata is a foundational element of modern information science. It connects raw data to human understanding and organizational systems. By providing context, it allows users to distinguish between similar and dissimilar resources. It also enables the grouping of related items and provides essential location information. Whether it is helping a researcher validate a statistic or helping a user find a specific web page, metadata acts as the invisible map of the digital world.