Kaur :- "Princess" and "Lioness"

Kaur is a name used by Sikh women either as the middle name, or as a last name. It can be regarded as a true surname. The tenth guru of Sikhs, Guru Gobind Singh Ji, made it mandatory for Sikh females to use the name Kaur and for Sikh males to use the name Singh when he administered Amrit (baptism) to both males and female Sikhs. All female Sikhs were asked to use the name Kaur after their forename and males were to use the name Singh. (Since 'Kaur' means 'Princess'&'Lioness', it acts as a symbol of equality among males and females.) This custom further confirmed the equality of both genders as was the tradition set by the founder of Sikhism, Shri Guru Nanak Dev Ji. It was intended to give women a sense of self-respect. Singh is also used by some females because Singh can be a last name. It is the most common last name used by Sikhs.
Kaur provides Sikh women with a status equal to all men. This was also intended to reduce the prejudice created by caste-typing based on the family name. Prejudice based on caste was still rampant during Guru Gobind's time (17th century). This particularly affected women who were expected to take their husband's family name upon marriage. The British required women to take on their husbands' names.
Sikh principles believe that all men and women are completely equal. Therefore, a woman is a princess and can lead her own life as an individual, equal to man. She does not need a man's title to raise her own status. Saying this would go against the principles stated in the Sri Guru Granth Sahib, the religious text of Sikhism. Guru Nanak Dev Ji states:

English translation	From woman, man is born; within woman, man is conceived; to woman he is engaged and married. Woman becomes his friend; through woman, the future generations come. When his woman dies, he seeks another woman; to woman he is bound. So why call her inferior? From her, kings are born. From woman, woman is born; without woman, there would be no one at all.

                                                      Punjabi 

		ਭੰਡਿ ਜੰਮੀਐ ਭੰਡਿ ਨਿੰਮੀਐ ਭੰਡਿ ਮੰਗਣੁ ਵੀਆਹੁ ॥ ਭੰਡਹੁ ਹੋਵੈ ਦੋਸਤੀ ਭੰਡਹੁ ਚਲੈ ਰਾਹੁ ॥ ਭੰਡੁ ਮੁਆ ਭੰਡੁ ਭਾਲੀਐ ਭੰਡਿ ਹੋਵੈ ਬੰਧਾਨੁ ॥ ਸੋ ਕਿਉ ਮੰਦਾ ਆਖੀਐ ਜਿਤੁ ਜੰਮਹਿ ਰਾਜਾਨ ॥ ਭੰਡਹੁ ਹੀ ਭੰਡੁ ਊਪਜੈ ਭੰਡੈ ਬਾਝੁ ਨ ਕੋਇ ॥   Source: http://en.wikipedia.org/wiki/Kaur