PDF stands for "portable document format" and is used in a multitude of government, academic and hard-copy document copying because of its viewable format by many different programs. Word and Excel documents can be transferred to PDF documents by saving them as such. Go to "File" and click "Save As." The save screen will pop up, which allows you to name your document. Underneath the bar you type the file name, you will see ".doc." Hit the arrow on the right of the box, click "PDF," and save. The file is now a PDF and can be read by any software program that can read PDF files.
HTML, which stands for "hypertext markup language," is another document format that enable anyone with an Internet browser to view your document. The process in creating an HTML document out of a Word or Excel document is exactly the same as above. HTML documents can be viewed by any Internet browser, but it should be noted that the formatting of your original document may by substantially different. While this is not a huge issue in Word, it can be in Excel.
Academic institutions are required to keep records of students' work in certain situations. This is more so in graduate and doctorate programs because of the publishing requirements at the doctorate level. PDF and HTML files allow anyone to view the documents on the Internet and also are easy to save for the institution. Also, new systems have been developed to prevent cheating and plagiarism in higher-education academics. These papers are cross referenced for plagiarism in a database. This database does not recognize non-PDF or non-HTML files so this may be another reason for the formatting change.