A PDF, or Portable Document Format, is a file type created by Adobe that preserves the formatting of documents, making them look the same on any device or operating system. It can contain text, images, and graphics, and is widely used for sharing reports, forms, and eBooks. PDFs are easy to view and print, ensuring that the document’s layout remains intact regardless of where it's opened. They can be secured with passwords and can include interactive features like hyperlinks and form fields, making them versatile for both personal and professional use.