This is a Java Question if you need more information/clarification let me know

I am confused about when the value of an instance variable is established. I thought it was established by assigning the value of the parameter to the instance variable. But the lesson that I am working on says that once an argument is passed during a method call, it will be used to give an instance variable an initial value. If that is the case, what is the difference between parameter assignment to an instance variable vs assigning value to an instance variable? Overview of What the program says To create objects with dynamic, individual states, we'll use a combination of the constructor method and instance fields. In order to assign a value to an instance variable, we need to alter our constructor method to include parameters so that it can access the data we want to assign to an instance. We've already seen a parameter in the main0 method: String[] args, but this is the first time we're using the parameter value within a method body. The Car constructor now has a parameter: String carColor: When a String value gets passed into Car0, it is assigned to the parameter carColor. Then, inside the constructor, carColor will be assigned as the value to the instance variable color. public class Car String color / / constructor method with a parameter public car string carcolor I/ parameter value assigned to the field color carcolor public static void main string args // program tasks Then the lesson states Now that our constructor has a parameter, we must pass values into the method call. These values are referred to as arguments; once they are passed in, they will be used to give the instance fields initial value. Here we create an instance, ferrari, in the main()method with "red" as its color field: public class Car string color public car String carcolor I/ assign parameter value to instance field color carcolor public static void main string args I/ parameter value supplied when calling constructor Car ferrari new Car "red" I am confused because I thought it was already established that the value of the instance variable was the value from the parameter that was assigned to it