As a final step before submitting your completed resume, you want to first save it in the word processor you're using. Then you will want to save this document again, converting it to a .pdf file.
You will want a .pdf file to submit online so that a potential employer's software doesn't change the formatting in your document. In addition by providing a .pdf file to a potential employer, you're submitting a document that anyone can open regardless of the word processor they use.
If you need help converting your document, please let me know.