Consistent with the "free" and open source concepts that has fueled the growth of the digital world (ie, the web and the internet), document files can and are being developed using several extensions. Some of the file documents include .txt and the popular .doc and .docx files with Windows Word.

And of course, there are also those using the .pdf (portable document format or PDF) extension, a file format developed by Adobe Systems, Inc to promote and improve the flow or exchange of documents which can be read on any computer operating system and also support forms, links (either internal or external), and javascript.  Some of the additional advantages of a PDF file include its allowing for: 1) a page-by-page readout of the documents in the same manner as they would look when printed out, and 2) the ability to undertake a keyword search within the document.

When one is familiar with the benefits of using a PDF file together with other document files, pdf conversion (either via word to pdf or sometimes the reverse, convert pdf to word) becomes an integral process. As they say, "the more the merrier", and this can be the case too with document files!