let and const are different ways of creating variables. As we know we create variable by using keyword var.
e.g. var name ="suraj" ;
With ES6 two different keyword were introduced let and const, var still works but you are highly encourage to use let and const.
* let: let is new var, its generally create variables like var. Its value is changeable
* const: const is a way of declaring variable when the value is not going to change and will remain same
Version of JavaScript that is compatible with ES6 and higher, new JavaScript frameworks like ReactJS, AngularJS uses new its concepts. It allows to write clean and robust code. Its important to understand because sometime its looks something strange version of JavaScript. As JavaScriptis evolving quickly and therefore new features can look different but it allow us as a developer to do more powerful things.
Some topic for next generation JavaScript are
2. Arrow Function
3. Export and Import
4. Classes, Properties and Methods
5. The Spread and Rest Operators
6. Destructuring
7. Reference and Primitive Types Refresher
8. Refreshing Array Functions
