ECMAScript or JavaScript?

When working with JavaScript, we find the term ECMAScript very often in books, blog posts, video courses, and so on. What does ECMAScript have to do with JavaScript, and is there a difference?

ECMA is an organization that standardizes information. Long story short, a long time ago, JavaScript was submitted to ECMA for standardization. This resulted in a new language standard, which we know as ECMAScript. JavaScript is an implementation of this specification (the most popular), which is known as ActionScript.