PDF stands for Portable Document Format. It is a file format used to present and exchange documents reliably, independent of software, hardware, or operating system. PDF files can contain text, images, and interactive elements, and they can be viewed, printed, and shared across different devices and platforms while maintaining the original formatting. The PDF format is widely used for documents such as manuals, reports, contracts, and forms, as it ensures that the document's layout and formatting remain consistent regardless of the device or software used to view it.