Format guides
What is a PDF file?
4 min read
PDF stands for Portable Document Format. Its entire purpose is that a document looks identical regardless of the device, operating system or software used to open it.
Why PDFs look the same everywhere
A PDF describes a fixed page: exact positions for text, vector shapes and images, with the fonts usually embedded in the file. Nothing reflows, which is why a PDF prints predictably and why it is awkward to read on a small phone screen.
Text PDFs versus scanned PDFs
A PDF exported from Word or a design tool contains real text you can select, search and copy. A PDF produced by a scanner or a phone camera contains a picture of text — visually similar, but not searchable and not editable without optical character recognition.
What PDF is good at
- Contracts, invoices and forms that must not reflow.
- Print-ready documents with embedded fonts.
- Combining many pages from different sources into one file.
What PDF is bad at
- Collaborative editing — use a word processor format instead.
- Responsive reading on small screens.
- Data you intend to analyse; export a spreadsheet rather than a PDF table.
Frequently asked questions
Can I edit a PDF?
Fixed-layout edits require dedicated software. In practice it is usually easier to edit the source document and export a new PDF.
Why can't I select text in my PDF?
It is a scan — the page is an image. OCR is needed to add a text layer.
Is PDF a secure format?
Password protection exists but is not a substitute for proper access control. Treat a PDF as readable by anyone who has the file.
PDF is the right answer when a document must look the same for everyone, and the wrong answer when the content still needs to change.