Portable Document Format, more commonly known as PDF, is a great standardized format to use for files. Adobe Acrobat is one of the premier PDF creation and editing programs available, but it is expensive. There are free alternatives for teachers to use.
I post all of my files for students as PDF files so that they can not be edited. Also, everyone can get a free PDF reader, such as Acrobat Reader to view the files so I don’t have to worry about a student not having the software to view the file.


I have used both applications to create PDF files from PowerPoint presentation handouts and then merge those PDF files with downloaded PDF files to create a single file guidebook that I use when teaching Google for Educators.
I love the ability to save any file as a PDF file. I use it to post files to my class website for students to use, as well as to make backup copies of files that I know I will be able to open on any computer, regardless of the operating system or software.