As Of May 1st 2017 the Office 365 License "Microsoft 365 Business" got some serious Upgrades
The full final list can be seen here
Exchange Online Archiving ( Unlimited Mailbox Size )
Azure Information Protection (AIP) Plan 1
Data Loss Prevention
Enterprise State Roaming
In-Place Hold and Litigation Hold
Microsoft Stream
Advanced Threat Protection (ATP)
Why you still might need an E3 License instead of Microsoft 365 Business
RDS Office activation
Dynamic Groups.
Advanced eDiscovery.