Product Reviews
You can use the Product Reviews app to add a customer review feature to your products. This lets your customers engage with your business, as well as each other, to encourage sales.
The Product Reviews app supports Google microdata (sometimes referred to as "rich snippets" or "structured data"). The app automatically adds an aggregate review score that appears in your search results on Google, which helps to increase traffic from organic searches:

In this section:
Using the app Add reviews to your website quickly and easily using the Product Reviews app.
Importing and exporting reviews Understand how to import and export reviews using the Product Reviews app.
Managing reviews Manage the reviews that you get on your store.
Customization Customize the look and feel of your reviews and review form.
Advanced customization Customize the look and feel of your reviews and review form with more advanced CSS.