What is gay,lesbian and love?

what is gay?
Gay originally meant in English happy. In modern usage, the term is often applied interchangeably with homosexual, though there are important differences between the terms. While "homosexual" relates specifically to sexuality, the term "gay" is a political or social marker. In homosexual terms: someone who practices homosexuality; having a sexual attraction to persons of the same sex. In gay relationships there are often a dominant and submissive partner, each depending to each personality
(Note: homosexuality means; a person who is sexually attracted to and/or has sex with someone of the same sex)

what is Lesbian?
A lesbian (lowercase L) is a homosexual woman. Lesbians are sexually and romantically attracted to other women. One could argue that one is not a lesbian (as a noun) but lesbian (as an adjective). This would depend on self identification, and is different for most lesbians/lesbian women. In simple terms; a woman whose sexual orientation is toward other women.
(Note: scientific researches proved that Gays percentages is higher than lesbians number, around the world, the reason of being gay or lesbian, is sometimes related to the production of female hormones in male body or male hormones in female body, and when the right male hormone is produced in a male more than enough this could lead to opposite reactions of producing the female hormones in the male body! .... Biology ... !

Why people fall in love?

Wow… that is a huge question, and I think you want the reason of some people falling in love with particular people… this is complicated, well in everyone body there are hormones that is alerted when the feel the presence of osmeone else certain hormones, that’s why your mind says “this is the one”…. Yes this is true, that’s why it’s not enough to see someone in a picture, and say this is my love, it’s takes your soul to feel the presence of this other soul around you, in work, school, house … that's also biology !
You may ask me How do you explain that? And I would say: science have found that two important characteristics, kindness and intelligence, are extremely important in the process of falling in love. And attractiveness is not connected to these things. These two attributes are things that people learn about someone from knowing them over time. Intelligence is important in all aspects of life, especially in love. But kindness is the strongest indicator for a successful long-term relationship.

Hope this helped … have a great day