This is a great, succinct breakdown of what gender is and is not, via Eater of Trees, who also points out that this applies to sex as well.
Genderbitch has written up a description of the image:
[A black and white column picture. The black side has white text and white pictures, the white side has black text and black pictures. Black side: “Gender is…” A transgender symbol, the merging of the venus and mars symbol into one ring with a merged mars arrow and venus cross on the third point on the upper left. Under it “A Spectrum”. The drama masks are the next symbol. “a range of expression”. The next picture is a person looking into a mirror wearing a hat. “how you relate to yourself”. The next picture is a Hello My Name Is Tag with the label “Me!” below it the final words “a personal identity.” On the white site the words “Gender is not…” underneath it the venus and mars symbol separate, below that the words “just male and female”. Below that is the dress stick figure and no dress stick figure bathroom signs, below it the words “defined by body parts”. Below that are the sexual orientation symbols (with the gender symbol symbol mixed in by accident it appears), the linked rings of two of each either mars symbol or venus symbol in various combos. Below that the words, “sexual orientation.” And finally, a picture of a molecular model of DNA, with the words below it “determined by chromosomes”]
So simple, and yet so difficult for so many people to understand or accept. Gender and sex exist on a spectrum, they aren’t binary (Gender Spectrum has a brief and pretty good explanation of this). This is proven both by biological research and by human history and experience. Trying to force a binary model on people has done incalculable, often irreversible harm to so many people.