What is Singh
Singh from Sanskrit sinha for lion, is an essential component of the name for a Sikh male. Every Sikh male name must end with 'Singh'. Historically, this was so ordained by Guru Gobind Singh on the Baisakhi day, 30 March 1699, when he inaugurated the Khalsa, introducing a new form of initiatory rites, khande di pahul.
What Is Kaur
Kaur, in modern day Punjabi means "princess" and is a name that is widely used as the second name by female Sikhs. This custom was first introduced in 1699 by Guru Gobind Singh ji, the tenth Sikh Guru when he administered Amrit (baptism) to both males and female Sikhs. All female Sikhs were asked to use the name Kaur (or Kour) after their forename and males were to use the name Singh, meaning "lion". This custom further confirmed equality to both genders as was the tradition set by the founder of Sikhism, Guru Nanak.
Stress on Sur Names
Today most of the Sikhs dont like to put Singh behind their name they put their surname behind. eg. Amarpreet Johal, Harpreet Ghotra these names are of singhs but they dunno put singh at their back. Guru ji gave us two surnames singh and kaur. Which means the sikhism follow MANAS KEE JAAT SABHEY EKEY PEHCHANBAOO. Putting surnames behind the names tells that people think they are of high caste or show themselves. Slowly slowly the separte identity of sikhs by name will be vanished. So this rising trend is very dangerous for Sikhism.
Like harpreet singh like to called himself Lucky and Jaswinder singh calls himself JAZZY B, BANNY A. etc. Hari singh call himself HARRY. A guy name khalsa when moved to america changed to GARRY. People are taking western culture in itself.