Office 365 E1 includes Microsoft 365 for the web and mobile apps only does not include the Outlook desktop client.

Limited to devices with integrated screens 10.1” diagonally or less.

Core Microsoft 365 for mobile includes Outlook, Word, Excel, PowerPoint, OneNote.Includes Word, Excel, PowerPoint, Outlook, OneNote, Publisher, and Access.Cancel anytime during your free trial to stop future charges. After your one-month free trial ends, your subscription will automatically convert into a 12-month paid subscription and you will be charged the applicable subscription fee.Learn more about data retention, deletion, and destruction in Microsoft 365. When a subscription is cancelled, all associated data will be deleted. Cancel your Microsoft 365 subscription in the Microsoft 365 admin center. Once your paid subscription begins, cancellation policies vary based on your status as a new customer, product, and domain selections on Microsoft.

Enterprise plans include around-the-clock phone support from Microsoft for all issues and have an unlimited seat cap.

Difference between o365 and office 2016