If you are not well introduced to the changes with the LineageOs Gerrit, then its a good news that LineageOs website gives you the information about every change with the new LineageOs update, the website was last updated on 20th Feb and it describes all the changes in the lineage os from 13 Feb till the date.
The last week’s new LineageOs update brought the CAF rebase with it. when LineageOS 14 was started, they based their sources from CAF to AOSP 7.1. They did this because CAF supported almost every Qualcomm devices that were built for LineageOs. But when Android 7.1 was released, CAF was not updated yet so the community developers decided to merge AOSP 7.1 on top of their current builds.
CAF has now been updated to 7.1 that releases all merged commits on top of the CAF 7.1 base. Now it will take less time to resolve the merged conflicts and the introduction of February’s security updates. The update also added AptX and AptXHD for supported platforms, but only for devices that supported it in their stock firmware.
If you need more information about the new LineageOs update, you can check out the source page here.The xda thread will be updated regularly by the dev to keep you updated.