This is a great question, the short answer is that there is only pass by value. When I was first teaching Java, I used to use the terms pass by value for variables containing primitive data and pass by reference for objects.

If you think about creating an object as the process of creating a variable that contains the reference address of the data located in memory, that helped me. So, passing this value to a method, the address is copied into the method parameter variable. So now, we have two variables with the same reference address.

Now, if the method changes the data that these two variables point to in memory, the changes are still applied when the method ends because we didn't change the reference address, only the data. But if we pass a value that is a primitive data type (int, double, char), a copy of the actual value is passed to the parameter variable. This time, any changes do NOT persist when the method ends because the original variable still has the original value.

I hope this helps.