How to understand CORS in simple terms?

Question

CORS

Hello. Help me understand what CORS is) I read various articles and can't get enough of it.

I do a fetch to a third-party API from the frontend, the browser swears. I understand correctly that if the service on the other side does not allow requests to itself through the API from any domains (or from mine specifically), then I won’t get rid of the error?

And in this case, you have to make requests to the API from the server (via the backend)?

Answer 1

Servers in a special header give a list of domains from which they can be accessed, and the browser checks that the script it runs is trying to make a request from an allowed domain. You understand correctly, the only way to get around is to make requests through an intermediary.