Indian restaurant

So, some of us went to an Indian restaurant the other day, and even though it clearly wasn't the first time eating an Indian food for any of us we couldn't answer some of the basic questions we had about Indian cuisine and religion - like, what type of Indian cuisine were we actually eating; what's the difference between Sikhism and Hinduism; and is there any religious reason for our waiter wearing a turbin? Here is what I could find from Wikipedia. Feel free to add anything more!

1. There have been many influences on Indian cuisine, but generally speaking there are northern, southern, and eastern styles. However, in American Indian restaurant, you typically see all of three kinds mixed. For example, Tandoori Chicken is considered "northern" for it's cooking style, and chicken tikka masala is considered "western" for it's British influence. Also, "northern" uses more meat ( e.g., kebabs), whereas "southern" is more vegetarian. In terms of their religion, Hinduism and Jainism are vegetarian, whereas Sikhism allows more meat from it's Muslim influence.

2. RELIGION: There is no "national" religion for India. The most prominent ones are Hinduism (80%), Islam (15%), Christianity (2%), Sikhism (2%), and about 1% for Buddhism and Jainism. Sikhism is the fifth largest religion in the world (after Christianity, Islam, Hinduism, and Buddhism), and although some consider it as a sect of Hinduism with influence from Islam, the Sikhism would strongly say not. For example, like Muslim, they believe in one creator God (called Vāhigurū), but like Hinduism, they believe in reincarnation as a path to salvation. Again, some would argue that Sikhism, which originated in India, is really a syncretism between Hinduism and Islam.

3. Lastly, the turbins that India males wear. Actually, this is only for the Sikhs. Their religion prevents them from cutting hair (I guess for life??), so they roll it up and use the turbin to keep it from flowing around too much and also from dirts. So, apparently Hindu Indians don't wear turbins. And, some other muslims from other countries wear turbins as well.

Any other ethnic food next week anyone???