What does PDF stand for?
Quick answer
PDF stands for Portable Document Format. It’s a file format created by Adobe and released in 1993 so that documents look exactly the same on any computer, phone or printer, with the same fonts, images and layout. Since 2008, PDF has been an open international standard (ISO 32000) that anyone can use.
Why PDFs were invented
In the early 1990s, sharing documents was frustrating: a file created on one computer often looked completely different, or wouldn’t open, on another. Adobe co-founder John Warnock launched the “Camelot Project” in 1991, aiming to let anyone send a document that would look identical everywhere. The result was PDF.
What makes PDFs “portable”
| Feature | Benefit |
|---|---|
| Fonts can be embedded | Text looks the same even if the reader doesn’t have the font |
| Fixed layout | Pages don’t reflow, so they print exactly as designed |
| Works everywhere | Readable on any operating system and most browsers |
| Compact | Images and text are compressed |
Special types of PDF
| Type | Used for |
|---|---|
| PDF/A | Long-term archiving |
| PDF/X | Professional printing |
| PDF/UA | Accessibility for people using screen readers |
| Fillable PDF | Forms with fields to type in |
From paid product to free standard
At first, Adobe charged for the software to read PDFs, and few people used them. In 1994, Adobe made Acrobat Reader free, and adoption grew. In 2008, Adobe handed the format to the International Organization for Standardization (ISO), making it an open standard.
PDF vs Word documents
| Word (.docx) | ||
|---|---|---|
| Best for | Sharing final versions, printing, forms | Writing and editing |
| Layout | Fixed | Changes with screen, fonts and settings |
| Editing | Harder | Easy |
Need to work with them? See how to combine PDF files and how to convert a PDF to Word.
A note on safety
PDFs can sometimes carry malicious links or code. Be cautious with PDF attachments from unknown senders; see what phishing is.
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