Gender Identity is a person's internal and individual experience of gender.
Gender Expression is how a person publicly expresses their gender. It can be presented through clothes, hair, make-up, body language, and voice.
Sex is the anatomical classification of people as male, female or intersex and is usually assigned at birth.
Gender used to be considered a binary spectrum (masculine/feminine, male/female) and the idea has evolved. People are able to identify as feminine, masculine, both, neither or some combination of. Some in the community liken it more to a cloud than a strict structure.
Instead of a gender binary spectrum like this:
We should consider it more like this:
Gender Unicorn
Trans Student Educational Resources, 2015. “The Gender Unicorn.” http://www.transstudent.org/gender.
Definitions adapted from:
Terminology is constantly evolving and changing and can be very personal. Each individual may find one term more offensive or preferable to another so always listen to the individual and their preferences. This is not a complete glossary, there are many additional terms about and used in the LGBTQ2S+ communities. See the glossary linked below for a more complete list.
Agender: A person who does not identify with any gender, or who does not experience gender.
Aromantic: Someone who does not experience romantic attraction to others. Romantic attraction is different from sexual attraction. Aromanticism can be considered a spectrum.
Asexual: Someone who does not experience sexual attraction for other individuals. Asexuality can be considered a spectrum.
Bisexual/Biromantic: An individual who is attracted to and may form relationships with at least two genders.
Cisgender: Identifying with the same gender that was assigned at birth. A gender identity that society considers to "match" the biological sex assigned at birth.
Crossdresser: Refers to people who wear clothing traditionally associated with a different gender to that which they identify. Some cross-dressers identify as trans while others do not. Some people may find this term offensive as it predates the evolution of current trans-related language. Cross-dressers may or may not have a gender identity related to the clothing they are wearing.
Female-to-Male Spectrum (FTM): Generally used to refer to anyone assigned female at birth and who identifies or expresses their gender as masculine all or part of the time. Some people prefer a term that does not imply that they were once female identified.
Gender Binary: The view that there are only two totally distinct, opposite, and static genders (masculine and feminine) to identify with and express. Although many societies believe this system to be universal, several cultures recognize more than two genders.
Genderfluid: Someone who experiences gender or genders as a fluid experience instead of static. Their gender may change depending on their feelings or the situation.
Genderqueer: A term under the trans umbrella which refers to people who identify outside of the male-female binary.
Intersex: General term used for a variety of conditions in which a person is born with reproductive or sexual anatomy, genetic makeup, or hormonal levels that do seem to fit the 'typical' definitions of male or female.
Male-to-Female Spectrum (MTF): Generally used to refer to anyone assigned male at birth and who identifies or expresses their gender as a female all or part of the time. Some people prefer a term that does not imply that they were once male identified.
Non-Binary (NB): A continuum or spectrum of gender identities and expressions, often based on the rejection of the gender binary's assumption that gender is strictly an either/or option of male/men or female/women. Can be a specific term of identification and/or an umbrella term.
Pangender: People who identify and/or express the many shades of gender. See also: Agender, Gender Non-Conforming, Genderqueer, Non-Binary
Pansexual/Panromantic: An individual who is attracted to and may form relationships with any or all genders.
Queer: A term that is becoming more widely used because of its inclusiveness. 'Queer' can be used to refer to the spectrum of non-heterosexual and/or non-cisgender people and provides a shorthand from 'LGBTQ'. It is a reclaimed term that was once and sometimes still is used as a hate term so use cautiously as there is a history to it in certain LGBTQ communities.
Transgender: A term that may be abbreviated to 'trans' or 'trans*' (asterisk was intended to include non-binary and/or non-static gender identities but as fallen out of use recently). This is an umbrella term for people whose gender does not match the gender they were assigned at birth. Identifying as trans is something that can only be decided by an individual themselves and is not dependent on surgery, hormone treatment or any other criteria.
Two-Spirit (2-Spirit): A term used by many Indigenous communities to describe people with diverse gender identities, gender expressions, gender roles, and sexual orientations. See Two-Spirit page for more details.
Definitions from:
Pronouns are personal and important parts of a person’s gender identity. As we use pronouns to refer to a person in place of their name, it is important to respect a person’s gender identity by using the correct pronouns, and not make assumptions based on their expression (clothing, hairstyle, etc.).
To make conversations around pronouns easier, there is a growing trend to introduce yourself with pronouns, use pronouns in email signatures or on a business card, and to start meetings. If you are unsure, ask or use gender neutral terms like they until you are able to ask. If you are in a group or there are other people around, don’t single out someone to ask their pronouns.
Making mistakes make us human, so if you use the wrong pronoun (either if you realize or someone corrects you), apologize, and correct yourself. For example: She has a good understanding of the topic. Sorry, they have a great understanding of the topic. Make sure your apologize is brief and doesn't focus on you. Misgendering is the experience of labeling others as a gender other than the one a person identifies with. Using the wrong pronouns intentionally or unintentionally is a form of misgendering.
This is a list of the most popular pronouns and examples on how they are used from the My Pronouns website (linked below). There are additional gender-neutral pronouns so always follow what other people would like to use.
She/Her/Hers: She is a writer and wrote that book herself. Those ideas are hers. I like both her and her ideas.”
He/Him/His: “He is a writer and wrote that book himself. Those ideas are his. I like both him and his ideas.”
They/Them/Theirs: “They are a writer and wrote that book themself. Those ideas are theirs. I like both them and their ideas.” Please note that although “they” pronouns here are singular and refer to an individual, the verbs are conjugated the same as with the plural “they” (e.g., “they are”). Also note that in this singular pronoun set many uses “themself” rather than “themselves,” although both are typically acceptable.
Ze/Hir: “Ze is a writer and wrote that book hirself. Those ideas are hirs. I like both hir and hir ideas.” Sometimes Zir is used instead of Hir.
No Pronouns: Use My Name (example for someone whose name is “Lan”): “Lan is a writer and wrote that book. Those ideas are Lan’s. I like both Lan and Lan’s ideas.”
Resources:
Etiquette
Gender Inclusive Language
One way to respect the many genders and identities people have is to remove gender from our language. Just as we wouldn't assume a person's gender if they were a single person standing in front of us, we also don't want to assume the gender(s) and pronouns of a group of people.
Instead of using gender-based assumptions try eliminating the gender language out of your sentence:
Instead of "ladies and gentlemen", or "boys and girls":
Instead of "he or she":
Depending on the context for "men and women, try:
If you need to talk get the attention of a specific person, you could indicate:
Resources
Becoming a Malaysian Trans Man: Gender, Society, Body and Faith by 
Gender and Sexuality in Modern Chinese History by 
Trans Power: Own Your Gender by 
