SharePoint 2016 New Features
Standalone installation is no longer supported. Earlier versions of SharePoint installs SQL Express edition along with SharePoint. But that is not the case anymore. In SP 2016, standalone installation requires separate installation of SharePoint edition and SQL installation.
Upgrade from 2010 to SP 2016 is not supported. SharePoint has to be upgraded to SP 2013 and database attach is the only supported migration path. Also SP 2013 will be considered as base for all the future releases of SharePoint.
SAML authentication is the first class citizen for authentication in SharePoint 2016. It will be the default. Windows claims, FBA still supported. But, clearly SharePoint is moving away from domain based authentication to cloud based authentication.
In previous version sending emails, messages etc were un-encrypted. 2016 encrypted communication between SharePoint and Messaging service.
The concept Web servers or App server is depreciated. In earlier versions, admin decides what are the role of each servers and he runs set of services. It was all based on documentation or Microsoft guide lines. In SP 2016, these documentations are converted into code and wrapped as Roles. This makes farm better responsive and better utilization of server resources. There are 3 main roles for SP 2016.
User Role: Where user actions are maintained. Like Excel Services, Sand Box Code, Subscription Settings, User Profile Service. This role is equivalent to web server roles in previous versions.
Robot Role: Takes task which is not initiated by user like Timer jobs, Search.
Caching Role: Supports distributed caching service. Also, health rule runs on every day and reports any deviation from the designated role.
Patching: Size of package and numbers reduced, thereby, reducing the server downtime.
Content Size: It was in Giga bytes in earlier versions and in SP 2016 it is scaled in Terra bytes.
Site collections: 100,000 Site Collections are supported in a single web application.
List threshold: It will more than 5000.
File Upload: Earlier version it was 2 GB. In SP 2016, it is increased to 10 GB and upload is done using background intelligence service (BITS) protocol rather than HTTP protocol.
Fast Site Collection creation: Creating site collections will be much faster. While provisioning new site collection at the database level, it makes a new copy the base template . That means no feature activation, no code execution.