Question from the Javascript test

There is no difference.prototype is just the standardized version while __proto__ only exists in Chrome.

prototype is a property of Function which allows to build the __proto__ when creating an instance with new.

__proto__ is a property of Object which serves as a template to declare theprototype of a classic object(Array, Number, Function,...).

When creating an object instance, the __proto__ property will be added to this instance and will itself contain an instance of the constructible function's prototype.