COMMENT, Header or Footer

Comment:
MS-Word 2016 allows you to add comments to your document, as a separate element of the document. Comments do not interfere with the main text and appear in their own area of the document. Comments are normally not printed when you print a document.
 
If you are using Word 2010 or Word 2016, the way comments are handled has been greatly changed when compared with older versions like Word 97. You can choose to add a comment, as noted below, by choosing the Comment option from the Insert menu. When you do, you will either see a comment balloon appear at the side of the document (if you are using Print Layout view) or you will see the Reviewing pane appear at the bottom of the screen (if you are using Normal view). Either way, you can type your comments, as desired.
 
You can insert a comment inside a balloon or a box that appears in the document margins. You also can show or hide comments from view.
 
How to insert a comment for selected text/paragraph?
Select the text/paragraph => Select Insert Menu =>Click Comment tool => Type your comments in the comment box.
 
For more understanding, look at the screenshot please:

Header or Footer
The header is a section of the document that appears in the top margin, while the footer is a section of the document that appears in the bottom margin. Headers and footers generally contain additional information such as page numbers, dates, an author's name, and footnotes, which can help keep longer documents organized and make them easier to read. Text entered in the header or footer will appear on each page of the document.
 
When you wish to create a multi-page document or a book using MS-Word often require a header at the top of each page and footer at the bottom of each page. So, you can insert the header and footer using header or footer tool in the Insert menu.
 
How to insert page number for the pages at the header of the document?
Select Insert Menu => Click Header Tool => Click on a design that’s you wish => Set your header & footer as you wished => Click Close tool.
 
For more understanding, look at the screenshot please: