Introduction to OOP Chapter 12: Implications of substitution: next previous audio real text

Meaning of Assignment?

What does it mean whan an instance of a class is assigned to another variable?
class Box {
	public int value;
}

Box x = new Box();
x.value = 7;
Box y = x;
y.value = 12;  // what is x.value?
Two possibilities:
Intro OOP, Chapter 12, Slide 13