Umbraco 7 modules are designed to contain specific functionality that then can be added to your website for future use. Any installed module can be customized and behavior of these modules can be modified as well.
Adding Umbraco 7 modules is not too complicated and you can do it in no time by going to Setting sections of the site and selecting StarterKit Master under Templates. You need to click on Customize Skin button on the toolbar and start Umbraco 7 customization.
You can use Umbraco 7 modules for updating navigation, sitemaps, social media feed or any other element of your Umbraco 7 site.
Discover more about Umrbaco 7 on get more information about the Umbraco.