Geisha are traditional, female Japanese entertainers, whose skills include performing various Japanese arts, such as music, singing and dancing. They also engage their clients with light conversation.

Traditionally, they began their training at a very young age. Although some girls were sold to geisha houses ("okiya") as children, this was not common practice in reputable districts. Daughters of geisha were often brought up as geisha themselves, usually as the successor ("atotori") or daughter-role ("musume-bun") to the okiya.

The first stage of training was called shikomi. When girls first arrived at the okiya, they would be put to work as maids. The work was difficult with the intent to "make" and "break" the new girls. The most junior shikomi of the house would have to wait late into the night for the senior geisha to return from engagements, sometimes as late as two or three in the morning. During this stage of training, the shikomi would go to classes at the hanamachi's geisha school. In modern times, this stage still exists, mostly to accustom the girls to the traditional dialect, traditions and dress of the "karyūkai".

After a short period of time, the third (and most famous) stage of training began, called maiko. Maiko are apprentice geisha, and this stage can last for years. Maiko learn from their senior geisha mentor ("one-san" meaning "older sister") and follow them around to all their engagements. The one-san/imoto-san (junior) relationship is extremely important. Since the one-san teaches her maiko everything about working in the hanamachi, her teaching is vital. She will teach her proper ways of serving tea, playing shamisen, and dancing, the casual talk of conversation, which is also important of a maiko to learn for future invitations to more teahouses and gatherings. One would suggest that geisha are prone to "flirt", but it is only their nature to seem demure and innocent. Regional variations exist as the han'gyoku of Tokyo are known for being sassy and the Kyoto maiko are known for being demure. The one-san will even help pick the maiko's new professional name with kanji or symbols related to her own name.

After a period as short as six months (in Tokyo) or as long as five years (in Kyoto), the maiko is promoted to geiko, which is a full-fledged geisha. Geiko charge full price for their time. Geisha remain geiko until they retire.

Source : http://en.wikipedia.org