Sometimes I hear people say \"a reference to a object\" and some say \"a instance of a object\" What is the difference?
We always use a reference to an object and cannot use the object directly, we can only use the reference. Object instance itself is in memory.
When we create an object, we get a reference. We can create more references:
var obj = {}; // a reference to a new object
var a = obj; // another reference to the object
A variable will hold a reference to an instance of an object.
The actual object is an instance.
The variable/variables used to access the object hold the references to it.