different types of birth?

Ashley
To me, a natural birth has always been vaginal, unmedicated. 
Then there's just your regular vaginal, and the csection. 
I'll hear a woman talk about a natural birth and then say something like "yeah they gave me epidural.." 
And I'm instantly confused about this. I have always thought natural meant.... Natural? So which is it? Is is a natural birth even though you were medicated or not?