A family of Microsoft word processing software products for creating web, email, and print documents.
Word's encryption of files is very, very strong. The only known method to break such password protection is brute force, i.e., trying increasingly complex candidates by combining dictionary words, upper and lower case characters, digits and symbols in orderly sequences until exhausting the various combinations.
For trivial candidates like "fox" or "qwerty" and words that appear in a dictionary, brute force will work. There are companies that break simple protection in a couple of hours and send you part of the document to prove they've accessed it. For a stipend, of course. Longer and more complicated passwords (DADsSilV3rDollar) would take a lifetime to be found.