ECMAScript

Another important thing to understand is that behind JavaScript, there is actually a language specification called ECMAScript, standardized by Ecma International in ECMA-262 since 1996. Though reading about it will be time consuming for now and not mandatory in order to understand further topics, you should know that this specification governs what JavaScript is and how it evolves. New language features and API proposals all go through the Ecma TC39 technical committee, which decides which ones are mature enough to make it into the specification. This all happens in the open, so don't hesitate to go and check it out.