PDFs

PDF stands for Portable Document Format, a file format created by Adobe in the 1990s to enable documents to be presented and shared independently of the software, hardware, or operating system used to create them. A PDF preserves a document’s fixed layout—fonts, images, and graphics—so it appears the same on any device and in any viewer, regardless of the original application.

In 2008, PDF was standardized as ISO 32000, formalizing a widely adopted specification. The PDF ecosystem has since expanded with specialized subsets such as PDF/A for archival, PDF/X for printing, PDF/E for engineering, and PDF/UA for accessibility. The most recent generation, commonly referred to as PDF 2.0, is ISO 32000-2, published in 2017, which preserves compatibility while adding enhancements.

Typical features include fixed layout, embedded fonts, support for vector graphics and raster images, hyperlinks, form fields, annotations, digital signatures, encryption, and metadata. PDFs can be interactive and may include multimedia in compatible readers. They are often compressed to reduce size and are self-contained, carrying all necessary resources within a single file.

Uses and considerations: PDFs are widely used for distributing manuals, reports, e-books, invoices, government forms, and scanned documents. The format is ideal for preserving appearance across platforms, but editing a PDF is not as straightforward as editing a source document, and viewability depends on fonts, resources, and security settings. Accessibility can be improved with tagged content and adherence to PDF/UA guidelines.

Related topics include creation and editing tools, viewers, standards, and considerations for long-term preservation and interoperability.