What are classes in ES6

In ES6, JavaScript classes are primarily syntactic sugar over JavaScript’s existing prototype-based inheritance. For example, the prototype based inheritance written in function expression as below,

function Bike(model, color) {
this.model = model;
this.color = color;
}

Bike.prototype.getDetails = function () {
return this.model + " bike has" + this.color + " color";
};

Whereas ES6 classes can be defined as an alternative

class Bike {
constructor(color, model) {
this.color = color;
this.model = model;
}

getDetails() {
return this.model + " bike has" + this.color + " color";
}
}