I have been learning about aggregate supply and demand. I have just read this answer which states:
"Aggregate supply is a relationship of price level and output. It is a function, or a curve, or a table. It is not a single value. If we know a particular price level, then we can determine the level of output that would correspond with that. The GDP for 2006 is determined by plugging in the price level of 2006 to the AS curve for 2006, and seeing what output is produced at that price level."
I don't understand, I have learnt the formula AD = C + I + G + (X - M). Wouldn't that give a specific numerical value?