Upgraded Power and External GPU Results
Under the hood, Apple adds Metal 2. This is a new way for your Mac to gain power and abilities by tapping into the GPU in your MacBook.
This is part of what allows the Mac to use machine learning to identify things in your photos and much more. It's the power behind support for Virtual Reality on Mac and it is essential for the new external GPU options.
With macOS 10.13.4, you can plug newer Macs into a USB C Thunderbolt 3 dock with an external GPU that unleashes more power when you are at your desk.
Whether you need better gaming support at home or you simply need more power for special effects, rendering, editing and other tasks -- this is an exciting addition to macOS High Sierra.