Object.create, basic understandings

    const obj1 = {test: "Hello"};
    const obj2 = obj1; 

obj2 is not the copy of obj1, but it is obj1 too. in javascript
objects are mutable, they are addressed by reference, not by value.

    console.log(obj1) //{ test: 'Hello' }
    console.log(obj2) //{ test: 'Hello' }
    obj1.test = "Hello Obj1";
    console.log(obj1) //{ test: 'Hello Obj1' }
    console.log(obj2) //{ test: 'Hello Obj1' }

Another case

    const obj1 = {test: "Hello"};
    const obj2 = Object.create(obj1);
    console.log(obj1) //{ test: 'Hello' }
    console.log(obj2) //{}
    console.log(obj2.test) // Hello

When you create an object using the Object.create then its values
become proto to the created object

    obj1.test = "Hello Obj1";
    console.log(obj1) //{ test: 'Hello Obj1' }
    console.log(obj2) //{}
    console.log(obj2.test) // Hello Obj1
    obj2.test = "Hello Obj2";
    console.log(obj1) //{ test: 'Hello Obj1' }
    console.log(obj2) //{ test: 'Hello Obj2' }
    console.log(obj2.__proto__) //{ test: 'Hello Obj1' }

It creates a new property for the test but still the prototype value
refer to obj1