What is a PDF? Meaning and uses explained

A PDF (Portable Document Format) is a file that shows a document exactly the same on every phone, computer and printer. Text, fonts, images and page layout are stored together inside the file, so a CV, invoice or form looks just as its author intended, whatever device opens it. The file extension is .pdf.

What does PDF stand for?

PDF stands for Portable Document Format. "Portable" means the document travels between devices and operating systems without changing. Adobe created the format in 1993, and since 2008 it has been an open international standard (ISO 32000), so anyone can make software that creates or opens PDFs without paying Adobe.

Why is PDF used everywhere?

• It looks the same everywhere. A Word file can change layout when fonts or software differ; a PDF does not.
• It is hard to change by accident. That makes it the normal format for contracts, invoices, receipts, bank statements, tickets and official forms.
• It prints accurately on A4 or US Letter paper.
• It can hold many pages, images, links, form fields and signatures in one file.
• It opens without special software: every web browser, iPhone, Android phone and computer can display it.

How to open a PDF

Double-click or tap the file. On Windows it opens in Microsoft Edge; on a Mac in Preview; on iPhone in Files or Books; on Android in Google Drive or your browser. You do not need to buy Adobe Acrobat to read a PDF. The free Adobe Acrobat Reader adds features such as comments, but it is optional.

How to make a PDF

• From a document: in Word, Google Docs or Pages choose File, then Save as or Download, then PDF. On Windows you can also print to "Microsoft Print to PDF".
• From photos or scans: use JPG to PDF, or HEIC to PDF for iPhone photos.
• From typed text: use Text to PDF or Markdown to PDF.
• Invoices, receipts and quotes: create them directly as PDFs with the invoice generator.

Can you edit a PDF?

Yes, within limits. A PDF is built for showing a finished document, so editing its text is harder than in Word. Everyday changes are easy with free browser tools: merge PDFs, split or remove pages, add a signature, fill in a form, add a watermark or page numbers. To reuse the words, extract the text.

Why are some PDFs so large?

Size comes mostly from images. A scanned page or a phone photo of a document can add several megabytes, while a page of typed text adds only a few kilobytes. To send a big PDF by email or upload it to a form with a size limit, use Compress PDF.

PDF vs Word: which should I send?

Send a PDF when the other person should read, print or sign the document as it is: CVs, invoices, contracts and applications. Send a Word file only when they need to edit it with you. Many job sites and government portals ask specifically for PDF.

Is a PDF safe to open?

PDFs from people and companies you know are generally safe. Like any attachment, a PDF from an unexpected sender can contain a malicious link, so do not click links or enter passwords in a PDF you were not expecting, and keep your browser and PDF reader up to date.

Frequently asked questions

What does PDF stand for?

Portable Document Format. "Portable" means the document looks the same on any device, operating system or printer.

Who invented the PDF?

Adobe, the company co-founded by John Warnock, released PDF in 1993. It has been an open international standard, ISO 32000, since 2008.

Is a PDF the same as a Word document?

No. A Word file (.docx) is made for editing and its layout can shift between computers; a PDF (.pdf) keeps a fixed layout for sharing and printing. Word can save a document as a PDF.

How do I open a PDF file?

Double-click or tap it. Every web browser, Windows, macOS, iPhone and Android phone can open PDFs for free, without extra software.

What is a PDF used for?

Sharing documents that must look the same for everyone and print correctly: CVs, invoices, contracts, forms, tickets, manuals and reports.