If you are printing on both sides of the paper, (double sided print) and binding your document, you may need mirror the margins, this means ensuring the space needed for binding is set up correctly on both sides of the printed paper.
This is easy to do and it is best completed before you start to create your files. Using Word, select Layout, click on Margins, Click Custom margins, Pages, Multiple Pages select Mirror Margins.
If you require a large margin on the binding edge, on the same margin page you can select a bigger gutter margin on the left or top.