That's for laptops that have a dedicated graphics card in addition to the CPU based graphics and Apple has allowed the ability for one to chose to run the dedicated graphics all the time, which consumes more power than allowing the computer to automatically switch between CPU and dedicated graphics on it's own.
If your machine has only CPU graphics or it's older and there is no switching option, then you won't see that choice in Energy Saver.
There is no "higher performance" graphics option in the terms if checked will give better graphics performance.
The "higher performance" just means it will use the more powerful graphics for low graphics uses that could save energy if the CPU graphics was used instead.
So it's a Energy Saver choice and only if have both types of graphics and Apple has allowed the option to choose.
Some might have been having issues with 3D games when the CPU graphics switch over to dedicated graphics, thus Apple started including that as a option recently.