If you put a dollar sign $ in front of a variable’s name, it means you want it to be an in/out variable.
That is, you can read its current value, but you can ALSO write a new value if you want
Suppose you have @State private var name = "" and you want a TextField to update it.
You’ll need $name in the text field.
But you’ll only need name in eg a static display Text that only needs read access.