What program records what happens only inside a window?

Question

Video

Greetings.
You need a program to record the screen, but not just the entire screen or part of it, but to record only inside the selected window. I understand that in many programs there is a function to capture part of the screen using a freely movable and draggable area, but it is the program that is interested in capturing a specific window.

Answer 1

Win+G

Answer 2

OBS