WordPress Defaults & Theme Options Panels
By default, WordPress comes built in with a ton of premium blogging and CMS functionality. Most of the time, the basic blog system can remain to be used as the news section if no need for a blog. On the other hand, certain circumstances may never need post, we can remove those items. Default WordPress dashboard widgets, WordPress widgetized widgets, alerts & more.
Another important feature to any custom WordPress theme would be an Options Panel. WordPress theme options panels allow developers to give specific options within the WordPress dashboard. Custom options such as background images, header layouts, text colors, heading sizes, & many simple options to allow the client to make more adjustments.
Another example of WordPress plugin support would be BuddyPress. If you want to run any form of social network with WordPress, BuddyPress can be a simple solution if your theme is compatible.