Parental Responsibility is all the rights, duties and responsibilities that a parent has for their child.
When you are very young your parents make your decisions for you but as you get older and more mature you develop the capacity to make your own decisions. Parental Responsibility for a small baby is very different from Parental Responsibility for a 16 year-old.
By the age of 16 a young person is able to make most decisions for themselves including things like leaving home, leaving school and getting a job. Although parents will still have a say in decisions it is more like advice and guidance to help you make good decisions.