Glossary / PDF Format
What Is PDF?
PDF (Portable Document Format) is a file format created by Adobe in 1993 that preserves the exact layout of a document across all devices and operating systems. PDF files contain text, images, fonts, and formatting in a single, self-contained file.
How PDFs work
A PDF file encapsulates a complete description of a fixed-layout document, including the text, fonts, vector graphics, raster images, and other information needed to display it. The format is defined by the ISO 32000-2 international standard, which ensures that any compliant reader can render the document identically.
Internally, a PDF is structured as a series of objects, pages, fonts, images, and metadata, organized in a cross-reference table that allows readers to quickly locate any part of the file. This structure supports features like random page access, incremental updates, and linearized (web-optimized) loading.
Common uses
PDFs are widely used for contracts, invoices, academic papers, government forms, user manuals, and any document where preserving exact formatting matters. Because the layout is fixed, a PDF looks the same whether opened on Windows, macOS, Linux, iOS, or Android.
Modern PDFs can also include interactive form fields, digital signatures, embedded multimedia, accessibility tags for screen readers, and encryption for security.
Related tools on fixtdoc
- Merge PDF , combine multiple PDFs into one document
- Compress PDF , reduce file size while keeping readability
- Split PDF , separate a PDF into individual pages