PDF is a special file format or file extension for creating, viewing, and printing electronic documents. PDF was developed by Adobe in 1993 as part of the digital workflow concept. PDF files can contain a variety of data ranging from text and images to interactive elements, buttons, hyperlinks, embedded fonts, videos, and more. This format is often used to store manuals, instructions, white papers, e-books, brochures, and the like. Reading files in PDF format is available to all users, usually standard programs for Windows or Mac are sufficient for this. Also, opening PDF files is currently supported by most modern Internet browsers. Any PDF files will always look the same, no matter what device or program they are open on.