It also means that some old features are eliminated or replaced - this is called deprecation. Microsoft publishes deprecation plans to alert administrators and developers so they can make timely changes to their solutions before a new version makes a feature break.
The typical pattern is to announce a feature deprecation more than one version in advance, sometimes supporting the old feature and the new feature, then issuing an update which eliminates the old feature.
Deprecation affects many aspects of Dynamics 365:
Apps or plug-ins may be deprecated, such as the Outlook Add-in for Dynamics which was replaced with the Outlook Dynamics App, or…