When do I need CORS?

I read about CORS on Wikipedia and stackoverflow.I get it that it allows the browser to make requests to a different hostIf my node.js server and browser are running on the same port and host, do I need cors?What if I add google tag manager, will that require CORS?Some advice is super appreciatedP.S searched for 'need cors' in this subreddit could not find any question asking this

Submitted November 12, 2019 at 07:33AM by mypirateapp