It can be really difficult finding all of the services and features that are included in a specific Office 365 subscription.
The Office 365 service comparison downloadable pivot table makes it really easy to see what it available for each subscription. This spreadsheet is updated on a frequent basis, so bookmark the link. I found this reference by chance when looking to see if DirSync and hybrid migrations are supported with the Exchange Online Plan 1 and 2 subscription.
The Office 365 Service Descriptions article forest is tedious to navigate but provides excellent information. I found the service comparison spreadsheet buried in here.
The Exchange Online Service Description is helpful too.
Ultimately, if you can’t figure out what services and features are available in a specific subscription from the information above, don’t hesitate to contact O365 support via the portal by submitting a service request or calling 800-865-9408 (United States). Support is a free service for those with either a trial or paid subscription.