Can someone explain to me what "real things" are in the context of the statement 'once you are using [insert language] for real things'? Is there a a difficult

Can someone explain to me what "real things" are in the context of the statement 'once you are using [insert language] for real things'? Is there a a difficulty barrier for considering an application real? A lines of code requirement? Is it like pornography and I'll know it when I see it?