The generated source dir for apt and kapt is different?

for example,An android project with the variant(Flavor1 + Debug)

  1. kapt
    The generate source files will be put into “build/generated/source/kapt/flavor1Debug”

  2. apt
    The generate source files will be put into “build/generated/source/apt/flavor1/debug”

what i mean is that “flavor1Debug” and “flavor1/debug” is so much different, why?

Why do you care about the difference?

i am developint a gradle plugin to support apt and kapt. i should know their difference.