Normal vaginal birth is the childbirth process which takes place without any form of medical intervention. Nowadays to alleviate the pain and speed up the delivery process medications might be used (you can choose not to opt for any medical intervention).
All in all, a normal delivery is, in other words, a completely natural delivery of a baby by the mother without any medical intervention.
During normal/vaginal delivery the primary focus is on how and in which position will the mother be comfortable delivering the baby. The mother can lead the whole process of labor and delivery.
The doctor and attending nurses, aid her while being alert for any kind of emergencies.