In Debian there is Simple Screen Recorder:
apt install simplescreenrecorder apt install simplescreenrecorderhttps://github.com/SeaDve/Kooha
It allows recording a rectangle/section of the screen, supports Wayland and records to webm by default - which most(?) browsers can play directly.
It's made it trivial to record short how-to videos for helping illustrate how to do something with a web app, or to illustrate visual bugs.