What is metadata? And what to know about Exif and IPTC

By teamnext Editorial Team

Metadata are data about data. They describe content such as books, emails, music, videos and, most importantly, files. Almost every file contains metadata: images, PDFs, Office documents, MP3s, videos.

In most cases, metadata follow defined standards. This improves interoperability and machine readability. Organizations can define their own metadata structures, but doing so often reduces compatibility with other systems.

This article focuses on metadata for digital images and photographs.

General background on metadata

The prefix meta comes from Ancient Greek and indicates a higher level. Metadata sit “above” the actual content data. The two layers are often called the metadata layer and the object layer.

Metadata often remain hidden. This can lead to unintentional disclosure when sharing files or sending messages. Metadata are therefore collected and analyzed at scale, for example by internet platforms and intelligence services.

Metadata in digital photography

Photo metadata can be stored:

  • inside the file itself, or

  • in a separate companion file, often called a sidecar file

Sidecar files are used less frequently today. Formats such as JPEG, TIFF, or WebP are container formats and can store metadata inside the file. Technical markers separate metadata blocks from the image data. These blocks are often referred to as the header because they are typically stored near the beginning of a file.

Which photo metadata standards exist?

In photography, several standards coexist:

  • Exif

  • IPTC-IIM

  • XMP

Since 2024, the C2PA standard for content provenance metadata has also become more established.

This article starts with Exif. It has been in use since 1995 and remains relevant for technical documentation.

Exif

Exif was developed by the Japanese camera industry. The acronym stands for Exchangeable Image File Format. Exif is supported by most digital cameras and smartphones. Many Exif fields are written automatically when taking a photo.

Examples of Exif fields include:

  • capture timestamp (date and time, often down to seconds)

  • focal length

  • camera model

  • aperture

  • shutter speed

  • ISO value

  • GPS data (coordinates, direction of view or movement, speed)

Exif also includes a few non technical fields such as image description or copyright that can be edited later. In practice, Exif remains primarily a technical metadata standard.

IPTC Information Interchange Model

IPTC refers to the organization that created a metadata standard in the early 1990s, the International Press Telecommunications Council. The technical implementation was the IPTC Information Interchange Model, IPTC-IIM. IPTC-IIM is considered outdated. For this reason, IPTC fields are commonly embedded via XMP in modern workflows.

Only a limited number of image formats fully support IPTC-IIM. The most important ones are JPEG and TIFF. IPTC metadata are mainly used to describe content.

Common IPTC fields include:

  • headline or title

  • copyright notice

  • caption

  • keywords

  • location (country, region, city)

  • contact information

  • urgency (scale from 0 high to 8 low)

XMP

XMP stands for Extensible Metadata Platform. It was developed by Adobe and first released in 2001. XMP is the most important format for descriptive metadata in image files today. Modern image formats often rely on XMP and do not provide full IPTC-IIM support.

XMP is flexible and can map established schemas, including:

  • Dublin Core

  • IPTC schemas such as IPTC Core and IPTC Extension

Why metadata matter in image management

Metadata can be indexed. This enables fast retrieval. This is especially relevant for text based metadata such as tags and captions. Adding unique identifiers and consistent creator attribution improves retrieval further.

Technical metadata such as file format, pixel dimensions, capture date, or GPS coordinates are also useful. They often power filters and structured search.

Metadata in the stock photography industry

In image archives, professional photography, and stock licensing, photo metadata have been essential for years. They have also become increasingly important in marketing, PR, and e commerce.

Metadata are necessary so teams and distributors can access current imagery quickly. Product photos can be tagged with product codes or manufacturer numbers. Attributes such as size, color, or price can be captured as well. If certain people appear frequently, tagging them improves search and reuse. Even subjective aspects such as mood, concepts, or interpretations can be documented via keywords.

Controlled vocabulary matters. Terms and spelling should be defined upfront and used consistently.

Metadata for rights and license management

Another key point is rights management. Managing image licenses, copyright, and consent documentation requires metadata, either attached to the file or stored in an image database.

Without metadata, professional license management is not feasible.

Conclusion

Managing photo metadata requires capable software. For individuals, local tools such as ACDSee or Adobe Lightroom can be sufficient. In organizations where multiple groups need to access the same library, a centralized solution becomes necessary.

In practice, this typically means a cloud based image management system.