JavaScript ES6, also known as ECMAScript 2015, is a major update to the JavaScript programming language. It introduced new features that make coding easier and more efficient, such as let and const for variable declarations, arrow functions for shorter function syntax, and template literals for easier string manipulation. These enhancements help developers write cleaner and more maintainable code. Additionally, ES6 brought in new data structures like Map and Set, which allow for more flexible data handling. It also introduced modules, enabling better organization of code by allowing developers to import and export functions and variables between different files.