What is difference between references and objects in java? [duplicate]

Answer 1

References are sort of pointers to a block of memory called objects.

GUI g1 = new GUI();

For explanation, let me break the above statement.

GUI g1;
g1 = new GUI();

1st step: g1 is a reference variable (pointer), not yet pointing to any valid memory location.

2nd Step: The second step allocates the memory for object of class GUI and the assignment operation make the reference variable g1 point to this object (memory location). The new keyword allocates the memory for the object of class GUI.