(just a warning i’m cis; this knowledge is coming from what i’ve heard from other queer people under the trans umbrella so it might not be. 100% life-lore accurate)

genderqueer can encompass nonbinary as far as i know - anyone who identifies as a gender that doesn’t match normal conventions (for example, identifying as kinda both male and female, or being neither) may take the label of genderqueer, but nonbinary generally refers to being off the traditional gender binary at least partly,, i assume that means they have a strong overlap but may not be the exact same? i assume people who fall under the category of both could probably choose which term they like better and identify with that one :P