Big Talk Education is a mainstream provider of RSE material and training for teachers.
Its glossary of sex and gender education terms for teachers and school staff states:
Gender identity does not necessarily relate to the sex a person is assigned at birth. Everyone has a gender identity, and a person’s feelings about their gender identity start early, the general consensus from child development specialists states that this is usually around the ages of 2-3.
Non-binary is an umbrella term for a person who does not identify as only male or only female, or who may identify as neither or both. Other terms which may be used by some people to describe their gender identity are Gender-queer (used by some people who do not wish to subscribe to a binary gender), Bi-gender (used by people who may identify with two genders), Agender (encompasses many different genders who describe their gender as neutral or do not have a gender) and Gender-fluid (used by people who feel their gender may change and is not linear or constant). If you meet someone who is trans, non-binary or another definition mentioned here it is important to be aware (by asking politely if you have not been told) about their preferred pronouns and name. The + in LGBTQ+ has been added to represent non-binary and the myriad of alternative gender classification or lack thereof.
The terms lesbian and gay are introduced to children from age 4 (UK reception year), as most schools now have at least one set of same sex parents, this is to help combat homophobic bullying. We explain that all families are unique and special to us so we should not tease anybody if their family is different to our own.
Pansexual refers to an emotional and/or sexual orientation towards any gender. This term recognises that many people do not fit neatly into a gender category like man/woman, for example, people who are trans or non-binary.
Demisexual refers to an individual who does not experience sexual attraction unless they have formed a strong emotional connection with another individual, often within a romantic relationship. This term emerged in the early 2010s and the ‘demi’ refers to the Latin term, meaning half, which represents that demisexuals are half way between Asexual and Heterosexual. However being a demisexual does not mean that someone has an incomplete sexuality or are half-sexual. Demisexuals do not get sexually attracted to anyone of any gender, but when a strong emotional connection is made, they may experience sexual attraction.