system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5 Why do pilots touch down and instantly take off again?

I live near a air force base and on occasion I’ll see a plane come in for a landing and basically just touch their wheels to the ground and then in the same motion take off again.

Why do they do this and what “real world” application does it have?
gpt
It's called a touch-and-go, and is mainly used to learn how to land the aircraft. Instead of coming to a full stop, the student takes off again, circles around and does another touch-and-go. The hardest part of the landing is the approach and touchdown, not bringing the aircraft to a stop, so touch-and-gos are how you practice without wasting time and airport space.