In the old days every experienced DBA updated SQL Server with only the latest servicepacks. CU’s (Cumulative Update packages) were available, but the advise was to only install those when a problem occurred that was fixed in the CU. ‘If it isn’t broken, don’t fix it!‘.
Occasionally CU’s would break smoothly running installations…..
Well, those were the old days.
Starting in 2016 Microsoft performs tests on CU’s the same way as on Servicepacks, and advises us to proactively install CU’s when available to get the most out of SQL Server. ‘If it isn’t broken, improve it!‘