Sexual Orientation is a person preference in either a male or female sexual partners. Some people are heterosexual which are interested in people of the opposite sex, others are interested in both men and women called ambisexual and a few numbers are engaged in with people that are the same sex as they which is called homosexual.
Different things causes people to have a particular sexual orientation.
It maybe in their gene or inborn hormonal factor and some experiences in love relationships or just bad experience in life. Some people try to change their sexual orientation from homosexual to hetersexual, but this doesn't be to successful. People now come public with their sexuality. Whether it is gay or lesbian.