What is web rtc and is it safe to un-check legacy rtc api

Safari has been quitting unexpectedly lately as well as service workers. I found in Develop that a lot of experimental items were checked and from similar questions, seemed safe to uncheck them as I am not a developer. WebRTC is also checked for legacy webRTC API. Do I need that? I do not recall checking anything in the develop category. I am using version 11.1.2. System too old to upgrade further.