Pointers purpose in game development

Question

Can I get a few explanations as to how pointers would help in game development?

Answer 1

~ swim ~ ohhhhhh and in most cases you want to pass by pointer so you dont make a “copy” and waste memory space? and in other cases you might want that that copy?

Answer 2

~ swim ~ so instead of me changing the value like

int myVar = 5

int main()
{
myVar = 6
cout << myVar << endl;
}

i’d change it like this?

int myVar = 5
int* ptr = &myVar

int main ()
{

cout << &myVar << endl;

}

Answer 3

~ swim ~ ohh and is that how we save memory ? sorry its just that the terms used confuse me like passing by value I dont understand the term “passing”