What is meant by player on Twitch?

Hi folks have twitch on my cell phone and absolutely no plan what is meant by player haha. Can someone help me?

That's just the video or the live stream. The video player, so to speak.

But when I'm in a stream, there's no option there: extensions

You are in the app, right? There it could be that the option does not exist. But only in the desktop version.

yes, you are in the app. Then I don't think there's an option.

Ok, thanks anyway.