PDF (Portable Document Format) is a file format that is commonly used to share documents electronically. Developed by Adobe, PDFs are designed to maintain the formatting of a document regardless of the software or operating system used to view it. PDFs can contain text, images, links, and even interactive elements such as forms and multimedia. The format is popular for a range of documents, including resumes, brochures, manuals, and eBooks. In addition, PDFs can be secured with passwords, digital signatures, and other security features to protect sensitive information. PDFs can be viewed and edited with a range of software, including Adobe Acrobat, Microsoft Word, and Google Docs.