Is a Realm from https://tc39.es/ecma262/multipage/executable-code-and-execution-contexts.html#sec-code-realms the same thing as a Realm from https://github.com/tc39/proposal-realms?
(Note: the proposal has since been renamed ‘ShadowRealm’)
As far as I can tell, yes. At the moment, Realms are an internal/conceptional construct for modeling program state. The proposal is about exposing this functionality as an API to use it in user land code.