The current version of SharePoint Online is based on SharePoint 2013, but many of the features are actually castrated.
The following is a list of the features that are limited by the Office 365 public Web site, and the solutions that can be bypassed:
You cannot create a content type on a Web site by using the UI, but you can create it with SharePoint Designer.
The site bar can be accessed directly via the URL [siteroot]/_layouts/15/mngfield.aspx, or it can be created with SharePoint Designer.
Child sites cannot be created through the UI, but can be created with SharePoint Designer. But after creation, there is no navigation menu.
Supported, but managed navigation is not supported
Unable to manage feature, but fortunately, someone solved Ashok Raja wrote a feature Manager Web Part
Cannot be found on the UI, but can be accessed [siteroot]/_catalogs/wp/forms/allitems.aspx
Cannot be found on the UI, but can be accessed [siteroot]/_catalogs/lt/forms/allitems.aspx
- SharePoint Sandboxed solutions/solutions Gallery
Sandboxed Solutions is still supported, but cannot be found on the UI and can be accessed by [siteroot]/_catalogs/solutions/forms/allitems.aspx