ECMAScript is a standard for several scripting languages, including JavaScript. Since 2015, a new version of the ECMAScript spec has been published annually. These versions-ES6, ES7, and ES8, respectively-don't deprecate any old syntax, so you'll be able to safely run legacy ES5 code in future web browsers or standalone JavaScript engines, but they also include lots of new syntax elements that make the process of writing JavaScript code more productive.