ECMAScript

ECMAScript is the official technical standard that the JavaScript programming language is based upon.

While “JavaScript” is the name of the language we write, “ECMAScript” (or ES) is the detailed specification that dictates exactly how the language must parse syntax and execute logic. The purpose of this standard is to ensure that code written in JavaScript runs consistently across different runtimes (like Chrome, Firefox, and Node.js).

Version History

The ECMAScript specification is updated yearly by a technical committee, adding new features to the language. Major milestones include:

• ES5 (2009): Introduced “strict mode” and native JSON support.
• ES6 / ES2015: A massive overhaul that introduced let and const, arrow functions, classes, and promises.
• ES8 / ES2017: Introduced the async and await keywords.

When reading documentation, you will frequently see features referred to by their ES release year (e.g., “ES6 arrow functions”).