3D aerobatics means flying a small airplane in a certain way to show off its cool moves. Imagine you have a toy airplane and you can make it do flips and spins in the air. That's kind of what 3D aerobatics is like, but with a bigger and more powerful airplane flown by a pilot.
The pilot will use the airplane's unique abilities to do things like flying upside down, hovering in one spot, and darting around like a hummingbird. This looks really neat and shows off how well the airplane can move, but it takes lots of practice and skill for the pilot to do it safely.
To do 3D aerobatics, the airplane needs to have special features like a powerful engine, a small and agile body, and special parts on the wings and tail that let it perform certain tricks. These are like special tools that help the pilot make the airplane do what they want it to do.
Overall, 3D aerobatics is like watching a really fancy and cool dance performance, but instead of people dancing, it's an airplane!