First published on MSDN on Sep 19, 2013
Each time when a service pack comes out for SharePoint, there's always a bit of confusion around how the Service Pack affects cumulative updates. Let me explain the state of SP2 with the June and August CUs. Although the June CU and SP2 came out at the same time, the June CU has a lower build number(14.0.7102.5000) than SP2(14.0.7015.1000). In order to build SP2, which is a longer process than building a CU, the SharePoint code base branches. SP2 and the June CU are in development at the same time. What this means is that in order for the later release(SP2) to include the changes from the earlier release(June CU), the code branches must be merged. Unfortunately this rarely happens when SharePoint Service Packs are released, due to tight deadlines. What this means is that Service Pack 2 does not include the changes that are in the June CU. If you install the June CU and SP2, you will get none of the changes that are included in the June CU. Since SP2 has a higher build number, it's version of SharePoint files overwrite the June CU's versions. Since Cumulative Updates are indeed cumulative, you'll need to install the August CU(14.0.7106.5000) to get the chances that were included in the June CU. I hope this helps folks understand a confusion situation.
