Portable Document Format is the creation of Adobe developers. The extension has been developed as a universally compatible doc format.
The format itself was developed back in the 1990s and belonged to Adobe until 2008. Since then ISO has been in charge of the extension’s development.
The PDF has several indisputable advantages. First of all, documents of this type are displayed in exactly the same way on any device regardless of the OS. Even different types of content can be integrated into this type of file: pictures, videos, charts, interactive buttons, etc. And the most important peculiarity of all is the size of files. This type of document can contain a huge amount of information. Moreover, such files can be easily compressed without any negative impact on the images' quality.
Despite its read-only nature, this file type can be edited via special programs and converted to other formats. Modern Internet browsers support the extension, so there is no need to install any apps. It is perfect for such types of documents as application forms, electronic manuals, contracts, agreements, and other official papers.