Enterprise Mobility + Security E5 includes new and advanced security capabilities that make up our holistic and innovative approach to security for the mobile enterprise. Some E5 capabilities were previously only available as standalone products, such as Microsoft Cloud App Security, or as products in preview, such as Microsoft Azure Active Directory Identity Protection, Azure Active Directory Privileged Identity Management, and Azure Information Protection.
I already have Office 365. How does it integrate with Enterprise Mobility + Security?
Microsoft Intune, included with Enterprise Mobility + Security, lets you manage Office 365 mobile apps so you can maintain the rich, productive Office user experience while Intune helps keep your corporate data secure. Additionally, Azure Active Directory, used by Office 365, enhances Enterprise Mobility + Security by including features like self-service password reset, group membership, and advanced machine learning-based security and usage reporting. For more information, read this post on the Enterprise Mobility + Security blog