Screen sharing

Hello

can someone tell me about screen sharing please?
I have noticed that in the company I work, they have selected the following : 'System preferences' > sharing > screen sharing > all users
My question is : can you see when someone is watching your screen or can they do this without you knowing? Do they always have to ask permission like for example when you work with a team viewer or does it work differently?
I'm not an administrator on my mac ( so it's all grey (I can't change it) and I think they are playing Big Brother ( (not sure if that is allowed)

regards
Marieke

Most likely, they can watch, without your knowledge.

While possible.... I'd suggest it's 'most' likely it's enabled for support purposes.

There's a screen sharing icon in the Menu Bar that appears when Screen Sharing is active.