It is all related with EBR (Edition Based Redefinition) and EBS's online patching.
What happens is;
During the online patching, you(adop) do the patching in the new edition (patch edition), while users and EBS are continuing to use the run edition.. So, patching doesn't require any downtime here.
During the cutover phase, you activate your patch edition of your database and you get the patched code directly... (Actually you make the patch edition to be your new run edition..)
Read my book. I cover all these with all of their details.