LGBT is an acronym connected with human sexuality. It means lesbian, gay, bisexual, and transgender, but it can refer to a community of people who are not heterosexual or cisgender. It is a word which has been used since the 1990s, and was a change from the previous acronym LGB or the group of words gay community, because many people in the LGBT community did not think that the group of words accurately described everyone it was referring to. The acronym has become more normal to use now and has been taken up by most sexuality and gender identity-related community centres in America, the English-speaking countries and in other countries where the acronym means something in their languages, such as France and Argentina.
People who are LGBT are romantically and/or physically attracted to people of their own gender (this is also known as their sexual orientation); or they act in a way that most people of their gender would not act (this is also known as their gender identity).
LGBT Facts for Kids. Kiddle Encyclopedia.