Help me figure out this int setup plz

th3chainrule:
So that does not necessarily mean that there is something physically attached to A0 right?

Such as an led.

Variable names only have meaning to the person writing the program. Naming a variable "LED" doesn't tell the Arduino anything, except that there is a variable named "LED". You could name it "Bob" and have the same effect.

I would assume if someone wrote code naming a variable "LED" and then assigned a number representing a pin to that variable, they expected a LED to be attached. Wouldn't you?