Answer 1

Hello, Albert Mungochi !
There is not much choice between the two methods. The basic idea is that when the JavaScript engine is given an object property for reading, it first checks the instance, and if this property is not present, it checks the prototype chain. Here is an example that shows the difference between a prototype and a classic:
prototypical
var single = {status: "Single"},
    princeWilliam = Object.create (single),
    cliffRichard = Object.create (single);
console.log (Object.keys (princeWilliam) .length); // 0
console.log (Object.keys (cliffRichard) .length); // 0
// Marriage event occurs
princeWilliam.status = "Married";
console.log (Object.keys (princeWilliam) .length); // 1 (New instance property)
console.log (Object.keys (cliffRichard) .length); // 0 (Still refers to prototype)
The classic instance method (inefficient, because each instance preserves its own property)