Why is the Doctor called Doctor Who?

Question

I have seen every episode of the new Doctor Who series. I understand the title is Doctor Who because no one really knows who the Doctor is, but what I don't understand is why the Doctor is called Doctor Who. As the Doctor says many times his name is "Doctor" Not "Dr. Who" but in subtitles and outside of the show he is called Doctor Who and not simply the Doctor.

Answer 1

very simple question. This show show from its name that Doctor Who is related to Who is Doctor. thats why Doctor Who character called Doctor Who. For more information you can search the site http://doctorwho.download-tvshows.com through online.

Answer 2

Its not his real name his real name is a secret that no one knows, all time lords get to choose there own nikname and he chose the doctor and they call him doctor who caus real people are not just called something like the doctor.