best response confirmed by Peter Whitehouse (Contributor)
Solution

I have seen a table that compares all the SKUs but it's apparently only meant for MS Partners, so can't be shared here.  You might want to reach out to one of these partners that can share these specifics with you.

 

From what I know anyway, Microsoft 365 Business is notable for:

 

Limited to 300 seats

business apps

Office 365 Business (Office 2016)

Subset of EMS features like MDM type features

Windows Autopilot

Windows 10 Business

 

Whereas Office 365 E3 has instead

 

Unlimited seats

Information protection - dlp, email encryption, rights management

Office 365 ProPlus

Compliance features like eDiscovery, mailbox hold, archiving

 

Then there are the similar common core Office 365 features in both like Teams, SharePoint, email, OneDrive, Skype etc.

 

Here is a nice set of resources as well this.

www.000webhost.com