Whenever we read a book about Object Oriented Programming, we reach the conclusion that the author is trying to convince us that an object can be anything. We, now, know that JavaScript is object based.
All objects belong to a class.
An object is a lot like an integer or a string. When you define a variable you create an instance of an object. Some objects, like Date, have more than one constructor function. The constructor is chosen depending on the arguments given in the call. For example, if you do not pass an argument in a Date object, the date will be set to the current system date and time.