Copy that just means Ok, thanks understood, I got it. It means you have understood a piece of information that someone has given.

One possible use is as a Miltary term. “Copy that” is used on a radio to show that the receiver of a message understands what’s been transmitted

It is like saying “ok” and tells the other person that you have heard and understood what they have said. It is meant to be used in a somewhat light and joking way. It is often used when someone requests something of you. For example: Person A: “Marianna, get some milk while you are at the store!” Person B: “Copy that”

A person, who copies everything you (or someone else) do

Copy that make same thing from that