Https://www.codecademy.com/courses/introduction-to-javascript/lessons/objects/exercises/pass-by-reference

Im not understanding the explanation in this lesson. What spaceship variable? There is a spaceship object but I just dont really understand the explanation. Help please, the bit im confused about specifically says: " * When we passed spaceship into that function, obj became a reference to the memory location of the spaceship object, but not to the spaceship variable. This is because the obj parameter of the tryReassignment() function is a variable in its own right. The body of tryReassignment() has no knowledge of the spaceship variable at all!"

https://www.codecademy.com/courses/introduction-to-javascript/lessons/objects/exercises/pass-by-reference

I found this on stack overflow which for me i think has helped a bit with the understanding. Was looking through a good few answers Is JavaScript a pass-by-reference or pass-by-value language? - Stack Overflow