Okay kiddo, imagine a big airplane that carries other smaller airplanes inside it. Now imagine that the big airplane can fly really really high up in the sky and it has the ability to launch those smaller airplanes while it's still flying up there. That's called an airborne aircraft carrier.
It's like having a big bird that carries around smaller birds on its back and drops them off to go fly and do tasks. In the same way, the airborne aircraft carrier can hold many different types of smaller airplanes that can go on different missions while still being connected to the bigger airplane.
This can be very helpful for situations where the smaller planes need to go far away or need to be launched quickly. The airborne aircraft carrier can stay up in the sky for a long time too, making it a really useful tool. In short, an airborne aircraft carrier is a big airplane that can carry smaller airplanes and launch them while still flying high up in the sky.