This was the final major feature update for Windows 8.1, which introduced performance improvements, refined language packs, and better hardware support for SD cards and USB debugging. AIO (All-in-One):
The Update 3 rollup (KB3000850) was a cumulative set of updates that provided: Windows 8.1 AIO x86-x64 (Portuguese) - Internet Archive FULL Windows 8.1 AIO Update 3 x86 x64 pt-BR
Update 3 was Microsoft's final major cumulative refinement for Windows 8.1, focusing on bridging the gap between tablet and desktop usability: Desktop Improvements This was the final major feature update for Windows 8
AIO builds typically allow users to select from several versions during the installation process: which introduced performance improvements