Aspire 2.1 introduced the ability to add and configure services through the Administration UI. In previous Aspire versions these were components that required file based configuration.
Example Services configuration screen
Product Categories
Services descriptions that show the 
icon are Premium, meaning they do not come in the Aspire Enterprise distribution and are licensed separately.
Services descriptions that show the 
icon are Aspire Enterprise bundled, meaning they do come in the Enterprise distribution.
Services descriptions that do not show either icon come in Enterprise distributions.
Group Expansion Services
SharePoint Services
Overview
Content Tools