How to describe methods in a JS object?

Question

JavaScript

Tell me what is the difference in the description of methods in the object? It's just that in the first case, the method is described in each instance of the object, and in the second case, in the prototype of the object. Roughly speaking in the second variant we avoid code duplication???
Thank you all in advance for your replies!

function Car(name, year) {
    this.name = name;
    this.year = year;
    this.getYear = () => new Date().getFullYear() - this.year;
}

function Car(name, year) {
    this.name = name;
    this.year = year;
}

Car.prototype.getYear = () => new Date().getFullYear() - this.year;

Answer 1

Not duplication, but the cost of creating this object () => new Date().getFullYear() - this.year;
In addition, in the first case, you assign a function to the property of the object, and in the second, you create a method