The MIME type application/vnd.pdf is used to indicate the presence of a PDF file within the message. As the name suggests, the this MIME type falls within the category of applications that covers a wide range of executable and non-executable file types across various different platforms. The PDF file type is a format used for transmitting documents. It is described as "Portable Document Format" and it was developed by Adobe Systems for easy document exchange.

This file type is emphatically used for its uniformity across various platforms. It was developed to be self-contained with all the necessary information of a document. PDF files are meant to display two-dimensional documents in a uniform manner across platforms, independent of both hardware and software. It was originally a proprietary format but then the International Organization for Standardization made it an open standard on 1 July 2008. Since then it has been utilized in many different softwares. The PDF document format is known for its advanced security features. It is one of the most secure ways of transmitting documents over the Internet. The in-built security features enable it to be password protected and encrypted, which are not possible for other standard document formats like the DOC and the LIT formats.

Learn how to open PDF file.