Ever wondered how Sitecore Update/Upgrade and Sitecore Patch Release are different? How to decide that you want a Sitecore Update or Patch?
What is an Update?
Sitecore releases Updates in timely fashion. These Updates normally have known bug fixes from previous versions and possibly any additional features/functionalities bundled. Every Update comes with Release Notes which have the details about – all fixed bugs, any new features and list of known bugs. Typically every Update have a revision number for ex.
Sitecore Experience Platform 9.0 rev. 171219 (9.0 Update-1). Decoding number 171219 tells that it was released on Dec-19 2017.
What is a Patch?
Sitecore release various patches for specific bugs. This can happen either when you raise a Sitecore Support Ticket or Sitecore releases the patch publicly. A Patch contains fix either for a particular Sitecore version/update or if feasible a specific bug fix for more than 1 Sitecore versions/updates. Typically Patches come with a particular Bug number mentioned in the Release Notes.
What should you opt – an Update or a Patch?
If you are already on a nearest latest version of Sitecore and struggling with a particular bug which can be resolved by a Patch – Go for it. Else Upgrade to a version which comes with a fix of that bug OOTB. But if you are looking for a new or advanced feature which is not available on your current version, obviously Upgrade is the only option left.
If you implemented a patch earlier and now you have upgraded to a version which come with the fix OOTB, you can rollback the patch by removing the files (Config/Dlls etc) which was included in the patch.
You can also find more differences as answers on this Sitecore Stack Exchange Question.