Learn about the most important new features in SharePoint Server 2016 as following :
MinRole
It is a set of predefined server roles, newly introduced in SharePoint Server 2016. SharePoint will automatically configure the services based on the server’s role. The performance of the farm is optimized based on that topology
https://technet.microsoft.com/en-us/library/mt346114(v=office.16).aspx
https://technet.microsoft.com/en-us/library/mt667910(v=office.16).aspx
SharePoint Add-ins
The name “apps for SharePoint” is changing to “SharePoint Add-ins”.
SharePoint Add-ins are self-contained extensions of SharePoint websites that you create, and that run without custom code on the SharePoint server
https://msdn.microsoft.com/en-us/library/office/fp179930.aspx
Zero-Downtime Patching
To patch a server in a SharePoint Server 2016 farm by using Zero Downtime Patching
https://technet.microsoft.com/EN-US/library/mt767550(v=office.16).aspx
Fast Site Collection Creation
Fast Site Collection Creation is a new capability in SharePoint Server 2016 IT Preview that improves Site Collection creation performance by reducing Feature activation overhead
Project Server 2016 installer is fully integrated into SharePoint 2016
The Project Server 2016 installer is fully integrated into SharePoint 2016—a separate installer no longer needs to be run on each server in the farm
https://blogs.office.com/2016/03/16/project-server-2016-rtm-is-now-available/
Finally , check this link for more details about new and improved features in SharePoint Server 2016
https://technet.microsoft.com/en-us/library/mt346121(v=office.16).aspx
