Microsoft 365 is a licensing bundle that Microsoft introduced in 2017. The bundle comes in two forms; Microsoft 365 Business and Microsoft 365 Enterprise. Microsoft Business is typically for a small to medium-sized businesses and contains tools such as Bookings, MileIQ and Microsoft Invoicing.
Microsoft 365 Enterprise combines Office 365 Enterprise, Windows 10 Enterprise and Enterprise Mobility + Security in one subscription. You have the choice between two plans; Microsoft 365 E3 or Microsoft 365 E5. If you currently have Office 365, Windows 10 and Enterprise Mobility + Security, then Microsoft 365 is the obvious choice, as you will be saving money moving to the package. But, the question is, which plan do you choose?
Microsoft will always push towards E5, and that is because the E5 plan has all E3 features plus the latest advanced threat protection, security and collaboration tools.
The extras in E5 can be broken down into three main areas:
Voice – get extra voice features such as Audio Conferencing, which allows your employees to set up Skype/Teams meetings with a conference number.
Security - get Advanced Threat Protection to help block malicious links in emails.
Analytics – get Power BI Pro which allows you to work with large amounts of data and convey them in an interactive dashboard.
These are just a couple of the features you get with E5, but you really need to look at each extra item and determine if it is right for your business. If you are just looking at the security piece, a lot of these features can be purchased as add-ons to your current plan. This is the same with Voice and Analytics.
If you require two out of the three, then it is worth the investment. For example, you want to move your phone system to the cloud and have the highest security features but perhaps don’t need Power BI, it is certainly cheaper than buying all add-ons. My recommendation would be to get a Microsoft partner involved to help match your requirements to licensing, as it can become quite overwhelming.
More information on Core's Microsoft licensing services: 
