What's the diference of Maiko and Geisha?

Last week I was watching Geisha and Maiko in Nara at Todaiji. Kikuno-san, (right) who is the leader of geisha in present day stood with beautiful blue kimono in front of people came to watch her and her disciple girl, Kikukame-san (left) who is such a lovely with prettey long-sleeved kimono and obi which was only allowed to wear under age of twenty (in Kyoto under fifteen). 

You probably know 'GEISHA' is a woman of the Japanese traditional arts, sometimes served sake and dance for man and very popular among foreign people but actually what is the difference of Geisha, Geiko and Maiko? In Tokyo these women are called Geisha, while in Kyoto they are called Geiko.  A Maiko is an apprentice of Geiko in Kyoto who should be teenager and not matured as adult lady.  The 'Maiko' in Chinese character indicates the meaning of a 'dancing child girl'. In Tokyo they are called as 'Hangyoku'. Maiko's prettiness are called 'Obokoi', which means 'very childish and cute' but when she grew up over twenty, then if she act like Maiko's dress up or childish behavior, people began to call her 'Ezukuro-shii' which means not cool or wise as a matured lady. So Geiko or Geisha dress up with chic colors, black is the typical color of kimono for them.