“Object” vs “Object Variable” in Java?

Question

I am teaching myself Java, and one of the review exercises in my book asks for the difference between an \"object\" and an \"object variable.\"

I know what an object is

Answer 1

I'll bite.

The Object is the instance itself, whereas the Object Variable is the reference to the Object.

Here's a contrived example:

Object o = new Object();
Object ref1 = o;

In his case, there is a single instance of the Object, but it is referenced by two Object Variables: o and ref1.

When an Object is no longer referenced by an Object Variable, the Object is garbage collected.