Not sure about forging being a marketing term. Forging in my understanding referee to the raw steel bring red hot and then manipulated by pressing, rolling or hammering into a desired shape. This often requires multiple cycles of reheating and manipulation. This is then often followed by CNC machining.

I also recall that grain structure is different in forged materials compared to casting.

A casted part will often be machined but not reshaped by e.g. hammering.