Configuration Manager “technical previews” are released by Microsoft on a monthly basis providing access to features before they are finalised and included in an update to the “current branch”.
Configuration Manager “current branch” versions are targeted for release 3 times a year with 18 months of security updates, and 4 months of critical updates. Thus to maintain access to critical updates you need to keep pace with applying each Current Branch version as it is released.
The naming convention of both technical previews and current branch releases is based on Year and Month, for example, 1910 is 2019 October.
Technical preview release history details can be found on the following links:
Current branch release history can be found on the following links: