Metadata is the data that defines or explains other data. It provides background information regarding a particular set of data and helps in easy identification and categorisation of the data.
For example, metadata of a jpeg image may contain information about the file name, file size, date modified, lens and camera used, etc. Similarly, a mobile’s metadata will comprise its make, model number, colour, company’s name, storage capacity, among others. Metadata can be used in a variety of data ranging from an image to a web page.
The traditional use of metadata can be seen in the use of library catalogues while more digital use can be seen in the use of metatags used in HTML. A metatag is a coded statement that tells about the essential aspects of a website. Metatags are used by the search engines to index the website so that the relevant information can be obtained by entering the keyword.
Also read: What is EULA? Why is it used?
Types of metadata
Although metadata can be put into various categories, there are three primary types of metadata: Structural, Administrative and Descriptive.
To put simply, it describes the structure of the data. It explains the relationship between the various components of the data and acts as a glue that binds those components together. This helps in proper navigation and thus helps in easy access to information. For example, the ordering of pages of the book.
We can look at the other way round too. Instead of breaking one big piece of data into smaller sets that are identified by metadata, we can now create extensive data, utilising metadata, from the smaller parts.
Information such as file type, date of file creation, type of file along with other pieces of information such as usage rights, data owner, and the usage information are covered under this type. In short, administrative metadata provides technical information about the concerned data. The information is usually external to the data and is used to understand the background of the data.
Administrative data can be of three types.
- Technical Metadata: Includes necessary coding and rendering information. For example, the shape of data structures, the number of bytes in a field, glossary, etc. Usually, this information is used by the technical team.
- Preservation Metadata: It contains the information necessary for preserving and archiving the data.
- Rights Metadata: This field specifies information regarding Intellectual Property Rights as well as the access rights.
It contains all the information necessary to describe data. Information may include a bibliography detailing the author and the titles, unique identifiers, date of publication, subject, along with information regarding the originality of data. Descriptive metadata is very useful is researches and in catalogues.
Benefits of Metadata
Metadata are highly beneficial for the following five reasons.
Metadata makes it much easier to search for the relevant information quickly. The information is highly categorised, and because of that, it becomes limited for the seeker.
Because of the descriptive metadata, how the data should be used along with the structure of the data is readily available to the user. This facilitates the proper use of the data.
The data is preserved for later use by the use of metadata and thus could be reused again.
Interoperability of the data
Metadata helps in identifying and understanding the relations among various resources and makes it easy to understand how data is interoperated among multiple systems.
Digital Identification of the data
Metadata helps in the digital identification of an asset by way of standard numbers assigned to the asset.
Former Senior Editor at Candid.Technology. Hemant has a keen interest in social issues and international relations.