This might be a rookie question.So I was just on Youtube,watching a studio session of a big producer,and one guy in the comments was basically saying that not many people know the difference between Gain and Volume.
So could anyone tell me if there's a difference,and if yes,what is it?

As far as I know, gain refers to the pre amplification (on the way in) and volume would be post amplification (on the way out).

So gain might be distorting it if it's pushing the limit while volume probably won't (assuming there's no limiter after the post).