Whenever you save a word document with 2013 or higher version, the default format is the word document (.docx). However, you can save your working file to many other formats such as PDF, HTML or even word 97-2003, etc. Please see below for details:
Step 1: With your working document open, click the "File" tab;
Note: If you checked "Don't show Backstage when opening or saving files", you will direct to Step 3.
Step 2: Click "Save as" from the navigation menu;
Step 3: Navigate to the location where you want to save the document;
Step 4: Click the triangle after the "Save as type" box and select "PDF" from the drop-down list;
Step 5: Click "Save" at the bottom and your word document is saved as a PDF file. This is very similar to save an Excel worksheet as the PDF file.
If you want to save your word document to another format, you can select any format from the drop-down list in step 4.
For example, if you want to save it to HTML file, you can select "Web Page" from the list.
If you want to save it to the word 2007-2003, you can select "Word 97-2003 Document"; or vice versa, select "Word Document" if you are saving a Word file from earlier version to current version.