Metadata is "data about data".
The term is ambiguous, as it is used for two fundamentally different concepts (types).
- Structural metadata is about the design and specification of data structures and is more properly called "data about the containers of data";
- descriptive metadata, on the other hand, is about individual instances of application data, the data content.
It provides information about a certain item's content.
The main purpose of metadata is
- to facilitate in the discovery of relevant information,
- more often classified as resource discovery.
Metadata also helps
- organize electronic resources,
- provide digital identification, and
- helps support archiving and
- preservation of the resource.
Metadata assists in resource discovery by "allowing resources to be found by relevant criteria, identifying resources, bringing similar resources together, distinguishing dissimilar resources, and giving location information."
For example,
- An image may include metadata that describes how large the picture is, the color depth, the image resolution, when the image was created, and other data.
- A text document's metadata may contain information about how long the document is, who the author is, when the document was written, and a short summary of the document.
Web pages often include metadata in the form of meta tags. Description and keywords meta tags are commonly used to describe the Web page's content. Most search engines use this data when adding pages to their search index.
Source from :
