What's Service Pack, CU, GDR In Sql Server

• Service Pack: A service pack contains a single package of previously released hotfixes, updates
• Cumulative Packs (CU): Cumulative Packs (CU) are the hotfix, minor feature enhancements
• General distribution release (GDR): Microsoft releases the GDR release, and it is specially related to the SQL Server security

Get the latest updates and version history for SQL Server:

https://learn.microsoft.com/en-us/troubleshoot/sql/releases/download-and-install-latest-updates