Gender is a social construct made up of various factors.
Broadly speaking, gender is the vibes that someone gives off. There are various diagrams used to explain this.
Action Canada For Sexual Health and Rights - Gender and Sexuality Galaxies – Comprehensive Sexual Health Education Tool
Gender Galaxy (pdf)
Scientific American - Graph of Sex & Gender
The Trevor Project - Gender/Sexuality Spectrum
Trans Language Primer - Gender Galaxy
Trans Language Primer - Gender Spectrum
Trans Student - Gender Unicorn
Trans Language Primer - Butch
Trans Language Primer - Drag
Trans Language Primer - Femme
Trans Language Primer - Gender Expression
Trans Language Primer - Gender Non-Conforming (GNC)
Trans Language Primer - Gender Presentation
Trans Language Primer - Stud
Butch is a Noun by Bear Bergman
Female Masculinity by Judith Halberstam (pdf)
DecolonizeAllTheThings - Under Construction: Decolonized Queer Masculinity(ies)
GLAAD - How I learned to embrace my masculine queer identity as a Black woman
Nature - Sex redefined
Plannned Parenthood - Gender Identity
Research Gate - Understanding the Bear Movement in Gay Male Culture
Simply Psychology - Sex vs. Gender: What’s the Difference and Why Does it Matter?
Trans Language Primer - Gender
Trans Language Primer - Gender Binary
Trans Language Primer - Gender Expansive
Trans Language Primer - Gender Fuck
Trans Language Primer - Gender Identity
Trans Language Primer - Gender Roles
Trans Language Primer - Gender Variant
Wikipedia - Gender