Differences between templates, themes, and Word styles
You have choices when you want to enhance the appearance of your document quickly. You can start creating a document by using a template, or you can apply themes and, if you're in Word, you can apply styles.
Templates are files that help you design interesting, compelling, and professional-looking documents. They contain content and design elements that you can use as a starting point when creating a document. All the formatting is complete; you add what you want to them. Examples are resumes, invitations, and newsletters.
To give your document a designer-quality look — a look with coordinating theme colors and theme fonts — you'll want to apply a theme. You can use and share themes among the Office for Mac applications that support themes, such as Word, Excel, and PowerPoint. For example, you can create or customize a theme in PowerPoint, and then apply it to a Word document or Excel sheet. That way, all of your related business documents have a similar look and feel.
Themes provide a quick way to change the overall color and fonts. If you want to change text formatting quickly, Word styles are the most effective tools. After you apply a style to different sections of text in your document, you can change the formatting of this text simply by changing the style. Word includes many types of styles, some of which can be used to create reference tables in Word. For example, the Heading style, which is used to create a Table of Contents.